The trapeziometacarpal joint (TMCJ) is the most common hand joint affected by osteoarthritis (OA), and trapezium implant arthroplasty is a potential treatment for recalcitrant OA. This meta-analysis aimed to investigate the efficacy and safety of various trapezium implants as an interventional option for TMCJ OA. Web of Science, PubMed, Scopus, Google Scholar, and Cochrane library databases were searched for relevant studies up to May 2022. Preferred Reported Items for Systematic Review and Meta-Analysis guidelines were adhered to and registered on PROSPERO. The methodological quality was assessed by National Heart, Lung, and Blood Institute tools for observational studies and the Cochrane risk of bias tool. Subgroup analyses were performed on different replacement implants, the analysis was done via Open Meta-Analyst software and P values < 0.05 were considered statistically significant. A total of 123 studies comprising 5752 patients were included. Total joint replacement (TJR) implants demonstrate greater significant improvements in visual analogue scale pain scores postoperatively. Interposition with partial trapezial resection implants was associated with the highest grip strength and highest reduction in the Disabilities of the Arm, Shoulder, and Hand score. Revision rates were highest in TJR (12.3%), and lowest in interposition with partial trapezial resection (6.2%). Total joint replacement and interposition with partial trapezial resection implants improve pain, grip strength, and DASH scores more than other implant options. Future studies should focus on high-quality randomized clinical trials comparing different implants to accumulate higher quality evidence and more reliable conclusions.
The Lateral Intercondylar Ridge (LIR) gained notoriety with arthroscopic trans-tibial Anterior Cruciate Ligament (ACL) reconstruction where it was mistakenly used to position the ‘over the top’ guide resulting in graft malposition. With anatomic ACL reconstruction some surgeons use the same ridge to define the anterior margin of the ACL femoral insertion in order to guide graft placement. However there is debate about whether this ridge is a consistent and reliable anatomical structure. The aim of our study was to identify whether the LIR is a consistent anatomical structure and to define its relationship with the femoral ACL insertion. In the first part, we studied 23 dry bone specimens. Using a digital microscribe, we created a 3D model of the medial surface of the lateral femoral condyle to evaluate whether there was an identifiable bony ridge. In the second part, we studied 7 cadaveric specimens with soft tissues intact. The soft tissues were dissected to identify the femoral ACL insertion. A 3D reconstruction of the femoral insertion and the surface allowed us to define the relationship between the LIR and the ACL insertion.Background:
Methods:
The transverse acetabular ligament (TAL) antomy is not a well explored aspect of the hip joint with limited morphological description in the reviewed literature. It is often used as an anatomical landmark for orientation of the acetabular component in total hip arthroplasty (THA). There is debate as to whether it represents an appropriate guide to cup placement in THA. Present descriptions in orthopaedic literature conside it as a single plane structure to which the surgeon can align the cup. The aim of the current study was to investigate the morphology of the TAL and it was hypothesised that the current description of it being a plane would prove insufficient. Seven dry bone hemi-pelves were reconstructed using a microscribe and rhinoceros 4.0 3D software to visualise attachment sites. Three hips from two female donors were dissected to expose the acetabulum and the TAL. This structure was removed and a footprint taken of its perimeter and attachment sites for measurement of ligament length, breadth and area of attachment from digital photographs. Finally, 3D models of the dissected acetabuli with an outline of the TAL and attachment sites were created as before.Introduction:
Materials and methods:
The term ‘resident's ridge’ originated from trans-tibial ACL reconstruction where a bony ridge on the medial surface of the lateral femoral condyle was mistakenly thought to represent the posterior articular margin of the condyle. This was then mistakenly used to position the ‘over the top’ guide resulting in graft malposition. With anatomical anteromedial ACL reconstruction some surgeons use the same ridge to define the anterior margin of the ACL femoral insertion in order to guide graft placement. However there is debate about whether this ridge is a consistent and reliable anatomical structure. There are no anatomical studies that define the features of the ‘resident's ridge’. Therefore, our aim was to identify whether the ‘resident's ridge’ is a consistent anatomical structure in non-operated human cadaveric femoral specimens. Using a digital microscribe, we mapped the medial surface of the lateral femoral condyle in cadaveric human femora denuded of soft tissue. This technique creates an exact 3D model of surfaces and from this we evaluated whether there was an identifiable bony ‘residents ridge’. 23 cadaveric specimens were used.Background:
Methods:
Peroneal muscle weakness is a common pathology in foot and ankle surgery. Polio, charcot marie tooth disease and spina bifida are associated with varying degrees of peroneal muscle paralysis. Tibialis Posterior, an antagonist of the peroneal muscles, becomes pathologically dominant, causing foot adduction and contributes to cavus foot posture. Refunctioning the peroneus muscles would enhance stability in toe off and resist the deforming force of tibialis posterior. This study determines the feasibility of a novel tendon transfer between peroneus longus and gastrocnemius, thus enabling gastrocnemius to power a paralysed peroneus tendon. 12 human disarticulated lower limbs were dissected to determine the safety and practicality of a tendon transfer between peroneus longus and gastrocnemius at the junction of the middle and distal thirds of the fibula. The following measurements were made and anatomical relationships quantified at the proposed site of the tendon transfer: The distance of the sural nerve to the palpable posterior border of the fibula; the angular relationship of the peroneus longus tendon to gastrocnemius and the achilles tendon; the surgical field for the proposed tendon transfer was explored to determine the presence of hazards which would prevent the tendon transfer.Introduction:
Method:
The purpose of this study was to provide an anatomical explanation for the presence of medial proximal tibial pain in patients with patellar mal-tracking without identifiable medial tibio-femoral compartment or proximal tibial pathology. Using cadaveric dissection we were consistently able to identify a connection between the medial patella and the medial proximal tibia including the medial hamstrings and the posterior oblique expansion. This connection is independent of the inferior patello-tibial ligament and has not previously been described in either anatomical or orthopaedic literature. The dimensions of this medial patello-tibial connection were measured using a digital microscribe. This technique also facilitated the creation of a three dimensional virtual representation of the patello-tibial connection. In the clinical setting, patients presenting with medial proximal tibial pain who had patellar mal-tracking as identified by clinical examination and merchant radiographs underwent MRI scanning of the knee to exclude any intraarticular or proximal tibial pathology. In those patients with patellar mal-tracking that had no evidence of proximal tibial or medial compartment pathology identified, we were able to correlate the MRI finding of oedema based at the proximal medial aspect of the tibia with the cadaveric dissection findings mentioned previously. In such cases we would recommend that treatment of the medial proximal tibial pain should focus on managing the primary pathology of patella mal-tracking. In conclusion we present a newly identified medial patello-tibial ligamentous complex that can explain the presence of medial proximal tibial pain in patients with patellar mal-tracking and no other proximal tibial or medial compartment pathology.
Non-invasive assessment of lower limb mechanical alignment and assessment of knee laxity using navigation technology is now possible during knee flexion owing to recent software developments. We report a comparison of this new technology with a validated commercially available invasive navigation system. We tested cadaveric lower limbs (n=12) with a commercial invasive navigation system against the non-invasive system. Mechanical femorotibial angle (MFTA) was measured with no stress, then with 15Nm of varus and valgus moment. MFTA was recorded at 10° intervals from full knee extension to 90° flexion. The investigator was blinded to all MFTA measurements. Repeatability coefficient was calculated to reflect each system's level of precision, and agreement between the systems; 3° was chosen as the upper limit of precision and agreement when measuring MFTA in the clinical setting based on current literature. Precision of the invasive system was superior and acceptable in all conditions of stress throughout flexion (repeatability coefficient <2°). Precision of the non-invasive system was acceptable from extension until 60° flexion (repeatability coefficient <3°), beyond which precision was unacceptable. Agreement between invasive and non-invasive systems was within 1.7° from extension to 50° flexion when measuring MFTA with no varus / valgus applied. When applying varus / valgus stress agreement between the systems was acceptable from full extension to 20° & 30° knee flexion respectively (repeatability coefficient <3°). Beyond this the systems did not demonstrate sufficient agreement. These results indicate that the non-invasive system can provide reliable quantitative data on MFTA and laxity in the range relevant to knee examination.
Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting. We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3 mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation. Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6 mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3 mm). These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.
Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting. We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation. Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3mm). These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.
The anatomy of the first metatarsophalangeal (MTP) joint and, in particular, the metatarsosesamoid articulation remains poorly understood. Its effect on sesamoid function and the pathomechanics of this joint have not been described. Fresh frozen cadaveric specimens without evidence of forefoot deformity were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in various positions of dorsiflexion and plantarflexion using a MicroScribe, enabling quantitative analyses in a virtual 3D environment. In 75% of specimens, there was some degree of chondral loss within the metatarsosesamoid articulation. The metatarsal surface was more commonly affected. These changes most frequently involved the tibial metatarsosesamoid joint. The tibial sesamoid had an average excursion of 14.2 mm in the sagittal plane when the 1st MTP joint was moved from 10 degrees of plantarflexion to 60 degrees of dorsiflexion; the average excursion of the fibular sesamoid was 8.7 mm. The sesamoids also move in a medial to lateral fashion when the joint was dorsiflexed. The excursion of the tibial sesamoid was 2.8 mm when the joint was maximally dorsiflexed while that of the fibular sesamoid was 3.2 mm. There appears to be differential tracking of the hallucal sesamoids. The tibial sesamoid has comparatively increased longitudinal excursion whilst the fibular sesamoid has comparatively greater lateral excursion. This greater excursion of the tibial sesamoid could explain the higher incidence of sesamoiditis in this bone. The differential excursion of the 2 metatarsosesamoid articulations is also a factor that should be considered in the design and mechanics of an effective hallux MTP joint arthroplasty.
Non-invasive assessment of lower limb mechanical alignment and assessment of knee laxity using navigation technology is now possible during knee flexion owing to recent software developments. We report a comparison of this new technology with a validated commercially available invasive navigation system. We tested cadaveric lower limbs (n=12) with a commercial invasive navigation system against the non-invasive system. Mechanical femorotibial angle (MFTA) was measured with no stress, then with 15 Nm of varus and valgus moment. MFTA was recorded at 10° intervals from full knee extension to 90° flexion. The investigator was blinded to all MFTA measurements. Repeatability coefficient was calculated to reflect each system's level of precision, and agreement between the systems; 3° was chosen as the upper limit of precision and agreement when measuring MFTA in the clinical setting based on current literature. Precision of the invasive system was superior and acceptable in all conditions of stress throughout flexion (repeatability coefficient <2°). Precision of the non-invasive system was acceptable from extension until 60° flexion (repeatability coefficient <3°), beyond which precision was unacceptable. Agreement between invasive and non-invasive systems was within 1.7° from extension to 50° flexion when measuring MFTA with no varus / valgus applied. When applying varus / valgus stress agreement between the systems was acceptable from full extension to 30° knee flexion (repeatability coefficient <3°). Beyond this the systems did not demonstrate sufficient agreement. These results indicate that the non-invasive system can provide reliable quantitative data on MFTA and laxity in the range relevant to knee examination.
Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting. We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation. Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6 mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3 mm). These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.
The anatomy of the first metatarsophalangeal (MTP) joint and, in particular, the metatarsosesamoid articulation remains poorly understood. The movements of the sesamoids in relation to the metatarsal plays a key role in the function of the first MTP joint. Although the disorders affecting the sesamoids are described well, the movements of the metatarsosesamoid joints and the pathomechanics of these joints have not been described. We have performed a cadaver study detailing and quantifying the three dimensional movements occurring at these joints. Fresh frozen cadaveric specimens without evidence of forefoot deformity were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in positions ranging from 10 degrees of dorsiflexion to 60 degrees of plantarflexion using a MicroScribe, enabling quantitative analyses in a virtual 3D environment.Introduction
Methods
Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 11 cadaveric specimens (10 fresh frozen, 1 embalmed). Distraction of the joint was performed as used intraoperatively for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches using a previous reported technique3. Disarticulation was performed and the marked surface area was quantified using an immersion digital microscribe, allowing a three dimensional virtual model of the articular surfaces to be assessed. The median percentage of accessible total talonavicular articular surface for the medial and dorsal approaches was 71% and 92% respectively. This difference was significant (Wilcoxon Signed Ranks Test, p<0.001). This study provides quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data support for the use of the dorsal approach for talonavicular arthrodesis.
The anatomy of the first metatarsophalangeal (MTP) joint and, in particular, the metatarsosesamoid articulation remains poorly understood. The movements of the sesamoids in relation to the metatarsal plays a key role in the function of the first MTP joint. Although the disorders affecting the sesamoids are described well, the movements of the metatarsosesamoid joints and the pathomechanics of these joints have not been described. We have performed a cadaver study detailing and quantifying the three dimensional movements occurring at these joints. Fresh frozen cadaveric specimens without evidence of forefoot deformity were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in positions ranging from 10 degrees of dorsiflexion to 60 degrees of plantarflexion using a Micro Scribe, enabling quantitative analyses in a virtual 3D environment.Introduction
Methods
Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 11 cadaveric specimens (10 fresh frozen, 1 embalmed). Distraction of the joint was performed as used intraoperatively for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches using a previous reported technique. Disarticulation was performed and the marked surface area was quantified using an immersion digital microscribe, allowing a three dimensional virtual model of the articular surfaces to be assessed. The median percentage of accessible total talonavicular articular surface for the medial and dorsal approaches was 71% and 92% respectively. This difference was significant (Wilcoxon Signed Ranks Test, p< 0.001). This study provides quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data support for the use of the dorsal approach for talonavicular arthrodesis.
The exact action of the The course of the distal Introduction
Methods and Materials
Isolated Disarticulation was performed and the marked surface area was quantified using a digital Microscribe allowing a three dimensional virtual model of the articular surfaces to be assessed. This study will provide quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the These data may provide support for the use of the dorsal approach for
The superficial anterior vasculature of the knee is variably described; most of our information comes from anatomical literature. Descriptions commonly emphasise medial-dominant genicular branches of the popliteal artery. Quantifying the relative contribution of medial and lateral vessels to the anastomotic network of the anterior knee may help provide grounds for selecting one of a number of popular incisions for arthrotomy. To describe the relative contribution of vessels to anastomoses supplying the anterior knee.Introduction
Aim
The superficial anterior vasculature of the knee is variably described; most of our information comes from anatomical literature. Descriptions commonly emphasise medial-dominant genicular branches of the popliteal artery. Describing the relative contribution of medial and lateral vessels to the anastomotic network of the anterior knee may help provide grounds for selecting one of a number of popular incisions for arthrotomy. The aim of this study is to describe the relative contribution of vessels to anastomoses supplying the anterior knee. Cadaveric knees (n = 16) were used in two cohorts. The first cohort (n = 8) were injected at the popliteal artery with a single colour of latex, and then processed through a modified diaphanisation technique (chemical tissue clearance) before final dissection and analysis. This was repeated for the second cohort, but with initial dissection to identify potential source vessels at their origin. Each source vessel was injected with a different colour of latex. The dominant sources were determined in each specimen. The majority of the specimens (n = 13; 81%) demonstrated that an intramuscular branch though the vastus medialis muscle was the dominant vessel. Anastomoses were most common over the medial side of the knee, both superiorly and inferiorly (3-5 anastomoses in all cases). Anastomosis over the lateral knee was infrequent (1 anastomosis in 1 specimen). The results suggest that anterior vasculature of the knee is predominately medial in origin, but not from the genicular branches as previously described. This network of vessels found in the anterior knee is thought to be the main supply to the patella, extensor apparatus, anterior joint capsule and skin. Optimum placement of incision for arthrotomy is a subject of debate. Considering the main blood supply to the anterior knee may help in choosing a particular approach.
The exact action of the Peroneus Longus muscle on the foot is not fully understood. It is involved in a number of pathological processes like tendonitis, tenosynovitis, chronic rupture and neurological conditions. It is described as having a consistent insertion to the base of the first metatarsal, but there have also been reports of significant variations and additional slips. Our aim was to further clarify the anatomy of the main insertion of the Peroneus Longus tendon and to describe the site and frequency of other variable insertion slips. The course of the distal peroneus longus tendon and its variable insertion was dissected in 20 embalmed, cadaveric specimens. The surface area of the main insertion footprint was measured using an Immersion Digital Microscibe and 3D mapping software. The site and frequency of the other variable insertion slips is presented. There was a consistent, main insertion to the infero-lateral aspect of the first metatarsal in all specimens. The surface area of this insertion was found to be proportional to the length of the foot. The insertion in males was found to be significantly larger than females. The most frequent additional slip was to the medial cuneiform. Other less frequent insertion slips were present to the lesser metatarsals. The main footprint of the Peroneus Longus tendon is on the first metatarsal. There appears to an additional slip to the medial cuneiform frequently. Although we are unsure about the significance of these additional slips, we hope it will lead to a better understanding of the mechanism of action of this muscle and its role both in the normal and pathological foot.
The arterial supply of the talus has been extensively studied in the past but there is a paucity of information on the arterial supply to the navicular and a very limited understanding of the intra-osseous supply to the surface of either of these bones. This is despite the likely importance of this supply in relation to conditions such as osteochondral lesions of the dome of the talus, and avascular necrosis and stress fracture of the navicular. Using cadaveric limbs, dissection of the source vessels was performed followed by arterial injection of latex. The talus and navicular were then removed en bloc, preserving the integrity of the injected arterial vasculature. The specimens were then processed using a new, accelerated diaphanisation technique. This rendered the tissue transparent, allowing the injected vessels to be visualised and then mapped onto a 3D virtual reconstruction of the bone. The vasculature to the subchondral surfaces of the talus and navicular, and the source vessel entry points that provide arterial supply into the navicular were identified. This study gives quantifiable evidence of the areas of consistently poor blood supply which may help explain the clinical pattern of talar and navicular pathology. It also provides as yet unpublished information on the arterial supply of the human navicular bone.
The arterial supply of the talus has been studied extensively in the past. These have been used to improve the understanding of the risk of avascular necrosis in traumatic injuries of the talus. There is, however, poor understanding of the intra-osseous arterial supply of the talus, important in scenarios such as osteochondral lesions of the dome. Previous studies have identified primary sources of arterial supply into the bone, but have not defined distribution of these sources to the subchondral regions. This study aims to map the arterial supply to the surface of the talus. Cadaveric limbs (n=10) were dissected to identify source vessels for each talus. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each talus was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined. This study will provide quantifiable evidence of areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. These data may help to explain the distribution and mechanisms behind the development of the subchondral cysts of the talus.
Talar neck fractures occur infrequently and are associated with high complication rates. Anatomical restoration of articular congruity is important. Adequate exposure and stable internal fixation of these fractures are challenging. We investigate the use of an anterior extensile approach for exposure of these fractures and their fixation by screws introduced through the talo-navicular articulation. We also compare the quality and quantity of exposure of the talar neck obtained by this approach with the commonly described combined medial/lateral approaches.Background
Aims
There is a paucity of information on the arterial supply of the navicular, despite its anatomic neighbours, particularly the talus, being investigated extensively. The navicular is essential in maintaining the structural integrity of the medial and intermediate columns of the foot, and is known to be at risk of avascular necrosis. Despite this, there is poor understanding of the vascular supply available to the navicular, and of how this supply is distributed to the various surfaces of the bone. This study aims to identify the key vessels that supply the navicular, and to map the arterial supply to each surface of the bone. Cadaveric limbs (n=10) were dissected to identify source vessels for each navicular. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each navicular was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined. This study will provide the as yet unpublished information on the arterial supply of the human navicular bone. The data will also give quantifiable evidence of any areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. This may help to explain the propensity of this bone to develop disorders such as osteochondritis, avascular necrosis and stress fractures which often have a vascular aetiology.
The extended lateral approach offers a safe surgical approach in the fixation of calcaneal fractures. Lateral plating of the calcaneum could put structures on the medial side at risk. The aim was to identify structures at risk on the medial side of the calcaneum from wires, drills or screws passed from lateral to medial. Ten embalmed cadaveric feet were dissected. A standard extended lateral approach was performed. The DePuy perimeter plate was first applied and 2mm K-wires were drilled through each of the holes. The medial side was now examined to determine the structures at risk through each hole. The process was repeated with the Stryker plate. The calcaneum was divided into 6 zones, by two vertical lines, from the margins of the posterior facet and a transverse line along the axis of the bone through the highest point of the peroneal tubercle. The DePuy and the Stryker plates have 12 screw positions, 5 of which are common. With both systems, screw positions in zone 1 risk injury to the medial plantar nerve and zone 3 the lateral plantar nerve. A screw through zone 2 compromises the medial plantar in both. Screws through zone 4 risk the lateral plantar nerve with the DePuy plate. Screws through zone 5 of the DePuy plate risk the medial calcaneal nerve. Zone 5 of the Stryker plate and Zone 6 of both are safe. There is significant risk to medial structures from laterally placed wires, drills or screws. Subtalar screws have the highest risk and have to be carefully measured and placed. The Stryker plating system is relatively safer than the DePuy perimeter plate with three safe zones out of six.
Talar neck fractures are associated with high complication rates with significant associated morbidity. Adequate exposure and stable internal fixation remains challenging. We investigated the anterior extensile approach for exposure of these fractures and their fixation by screws introduced through the talo-navicular articulation. We also compared the quality and quantity of exposure of the talar neck obtained by this approach, with the classically described medial/lateral approaches. An anterior approach to the talus between the tibialis anterior and the extensor hallucis tendons protecting both the superficial and deep peroneal nerves was performed on 5 fresh frozen cadaveric ankles . The surface area of talar neck accessible was measured using an Immersion Digital Microscribe and analysed with Rhinoceros 3D graphics package. Standard antero-medial and antero –lateral approaches were also carried out on the same ankles, and similar measurements taken. Seven talar neck fractures underwent operative fixation using the anterior approach with parallel cannulated screws inserted through the talo-navicular joint. 3D mapping demonstrated that the talar surface area visible by the anterior approach (mean 1200sqmm) is consistently superior to that visible by either the medial or lateral approaches in isolation or in combination. Medial malleolar osteotomy does not offer any additional visualisation of the talar neck. 3D reconstruction of the area visualised by the three approaches confirms that the anterior approach provides superior access to the entirety of the talar neck. 5 male and 2 female patients were reviewed. All had anatomical articular restoration, and no wound problems. None developed non union or AVN. The anterior extensile approach offers superior visualisation of the talar neck in comparison to other approaches for anatomical articular restoration. We argue that this approach is safe, adequate and causes less vascular disruption.
Limited wrist arthrodesis has been shown to be an effective treatment for the degenerative and unstable wrist, abolishing pain but limiting motion. The aim of the study was to assess the effect of excision of the scaphoid and triquetrum on wrist joint range of motion, in the setting of a limited midcarpal arthrodesis. Twelve cadaveric wrists had the range of motion measured, before and after, ulnar four-corner fusion (lunate, capitate, triquetrum and hamate fusion). This was measured again following sequential scaphoid and triquetral resection. Scaphoid excision after four-corner arthrodesis resulted in a 12 degrees increase in the radio-ulnar (R-U) arc and 10 degrees increase in the flexion-extension (F-E) arc range of motion. Subsequent excision of the triquetrum, to produce a three-corner fusion, further increased R-U arc by seven degrees and F-E arc by six degrees. These results demonstrate that three-corner fusion with excision of scaphoid and triquetrum results in improvement in wrist motion when compared to four-corner fusion with scaphoid excision alone. From this we conclude that triquetrum excision should be considered in Scapholunate advanced collapse (SLAC) wrist reconstruction to improve residual wrist range of motion.
