header advert
Results 1 - 16 of 16
Results per page:
Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_3 | Pages 7 - 7
1 Apr 2015
Bhattacharyya R Ker A Fogg Q Joseph J
Full Access

Background:

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.

Methods:

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.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_7 | Pages 17 - 17
1 Apr 2014
Bhattacharyya R Ker A Fogg Q Joseph J
Full Access

Background:

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.

Methods:

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.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_31 | Pages 36 - 36
1 Aug 2013
Herd J Joseph J McGarvey M Tsimbouri P Bennett A Meek R Morrison A
Full Access

Allogenic blood is a finite resource, with associated risks. Previous studies have shown intra-operative cell salvage (ICS) can reduce allogenic transfusion rates in orthopaedic surgery. However, recent concerns regarding the efficacy and cost-effectiveness of ICS mean we must continually re-assess its usefulness in current practice. This study was carried out to review the use of ICS, to establish if its use has led to a reduction in patient exposure to post-op allogenic transfusion.

All orthopaedic patients who underwent ICS and re-infusion between 2008–2010 in the Southern General Hospital (SGH) were audited. The Haemoglobin (Hb) drop, volume of blood re-infused and post-op allogenic transfusion rates were recorded. The revision hip group was compared to a similar SGH cohort, who underwent surgery by the same surgeons between 2006–2008, and a pre-2005 control group. The Cell Saver (Haemonetics) machine was used.

The proportion of patients who received a post-op allogenic transfusion fell by 55% in the 2008–2010 ICS cohort compared with the control, and by 40% compared with the previous ICS study group. In both instances, this was accompanied by a statistically significant (p<0.001) reduction in mean number of units transfused per patient.

ICS has been shown to be effective in reducing rates and volume of post-op allogenic transfusion in patients undergoing revision hip surgery at the SGH. ICS has been used with increasing efficiency over time.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_31 | Pages 37 - 37
1 Aug 2013
Leitch A Joseph J Murray H McMillan T Meek R
Full Access

Over 70,000 hip fractures occur annually in the UK. Both SIGN (111) and NICE (124) give guidance on optimal management of these patients. Both suggest cemented hemiarthroplasty should be used in those without contra-indications, as cemented implants are associated with less thigh pain, subsidence and a better functional outcome. Cardiorespiratory compromise secondary to bone cement implantation syndrome (BCIS) is however a concern in those with pre-existing cardiorespiratory disease (NYHA grade 3–4, pulmonary hypertension) or pathological fracture [3].

The aim of our study was to audit the practice of a University of Glasgow hospital with regard to cemented hemiarthroplasty.

We retrospectively reviewed data on all patients treated with hemiarthroplasty for hip fracture at the Southern General Hospital between 01/01/12-02/04/12. Patient demographics, pre-operative plan, procedure performed, ASA grade and pre-morbid mobility were recorded.

Results

Twenty-three hemiarthroplasties were performed. The median age was 82 (70–101). No patient aged over 90 underwent cemented hemiarthroplasty. Cemented implants (JRI, Furlong) were used in 26% (n=6) while 74% (n=17) underwent uncemented (Stryker, Austin-Moore) hemiarthroplasty. ASA grade was recorded in eight (35%). There were four ASA-2 patients (mild systemic disease not limiting activity) of which 75% underwent uncemented hemiarthroplasty. Pre-morbid mobility was recorded in eight (35%). All three independently mobile patients underwent uncemented hemiarthroplasty. Six (26%) had a documented pre-operative plan with regards to cement use.

This study highlights the disparity between current recommendations and our Centres’ practice. Most notable were: poor recording of pre-operative mobility, poor documentation of a pre-operative surgical plan, the low use of cemented fixation even in fit mobile patients and the lack of ASA grade recording (stratification of risk) by our anaesthetic colleagues.

We suggest a documented pre-operative discussion between the surgeon and anaesthetist to establish BCIS risk and decide on use of cemented arthroplasty taking into account age and mobility.


Cubitus varus following paediatric supra-condylar humeral fracture represents a complex three-dimensional malunion. This affects cosmesis, function and subsequent distal humeral fracture risk. Operative correction is however difficult with high complication rates. We present the 40-year Yorkhill experience of managing this deformity.

From a total of 3220 supracondylar humeral fractures, 40 cases of post-traumatic cubitus varus were identified.

There were ten undisplaced fractures, treated in cast, and thirty displaced fractures. Five were treated in cast, thirteen manipulated (MUA), four MUA+k-wires, seven ORIF (six k-wire, one steinman pin) and one in skeletal-traction.

Sixteen malunions were treated operatively. The mean pre-operative varus was 19°. All had cosmetic concerns, three mild pain, one paraesthesia/weakness and three reduced movement (ROM). The operative indication was cosmetic in fifteen and functional in one (concern about instability).

Twelve patients had lateral closing-wedge osteotomies; three complex/3D osteotomies (dome, unspecified rotational, antero-lateral wedge) and two had attempted 8-plate guided-growth correction.

Complications occurred in eight patients (50 %): Fixation was lost in three (two staples, one k-wiring), incomplete correction in six (both 8-plates, both staples, two standard plates) and one early wound infection requiring metalwork removal resulting in deformity recurrence. One patient underwent revision lateral wedge osteotomy with full deformity correction but marked ROM restriction (20–100°) secondary to loose bodies.

Those without complications were satisfied (50 %). All patients with residual deformity were unsatisfied. 1 patient with keloid scarring was unsatisfied despite deformity correction.

Varus malunion is uncommon (1 %) but needs to be guarded against. It tended to occur in displaced fractures treated with MUA and cast alone. We therefore recommend additional pin fixation in all displaced fractures.

Deformity correction should only be attempted in those with significant symptomatic deformity due to the high complication/dissatisfaction rates. Staple osteotomy fixation and 8-plate guided growth correction are not recommended.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_30 | Pages 18 - 18
1 Aug 2013
Joseph J Fogg Q Dearing J
Full Access

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.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_30 | Pages 19 - 19
1 Aug 2013
Joseph J Dearing J
Full Access

We present a simple seated dial test that can be used by a single examiner in the acute or chronic situation to diagnose posterolateral corner knee injury.

In the acute setting a traditional prone dial test can be cumbersome and painful for patients. Therefore a supine technique can be utilised, however this requires an assistant in order to hold the knees together with the tibia in a reduced position. We therefore utilise a seated technique in which the patient sits with their knees flexed over the edge of the examination couch. The patient is then able to hold their knees together, negating the need for an assistant. The sensitivity of a dial test is improved if the knee is reduced and so with this technique the tibia will be held in the anatomical position by the examination couch.

The patients' feet are grasped with both medial malleoli together and then an external rotation moment is exerted at 30 and 90 degrees of flexion measuring the thigh-foot angle or visualising the tibial tuberosities. A positive test being 10 degrees or more of increased external rotation in the affected knee.

This test is similar to the Spin test however it relies on the tactile sensation of posterolateral tibial rotation. This can be difficult to elicit in the acute situation due to haemarthrosis. Simultaneous side-to-side comparison is also not possible. A further disadvantage of the Spin test is that it can only be performed at 90 degrees of flexion and so only applies in combined PCL and posterolateral corner repair.

In conclusion we believe that this modification of the standard dial test is a simple to perform accurate method for assessing posterolateral corner knee injury in the acute and chronic setting.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_30 | Pages 14 - 14
1 Aug 2013
Joseph J Anthony I Jones B Blyth M
Full Access

The purpose of this study was to evaluate the effect of body mass index (BMI) on patients undergoing primary total knee arthroplasty for osteoarthritis. Data was collected on 664 patients at 4 centres all of whom received a Depuy PFC Sigma prosthesis. Data collected included patient demographics, Oxford Knee Score (OKS), American Knee Society Score, SF-12, complications of surgery and the need for revision.

14% of patients had a BMI<25, 35% were overweight (BMI-25–30), 32% suffered from Grade 1 obesity (BMI-30–35) and 19% had grade 2 obesity (BMI>35). Obese patients were more likely to be female, have a higher ASA grade, present at a younger age and do sedentary work or no work at all. Pre-operative Oxford knee score was significantly worse in the BMI>35 group (p<0.001).

After surgery there was a significant improvement in functional outcome measures at 5 years post-operatively with all BMI groups improved by an average of 18 or 19 points in the OKS. However because those patients with high BMI have poorer pre-operative Oxford scores their post-operative scores were lower compared to patients with a normal BMI. Similar findings were noted with range of motion of the knee joint.

Overall complication rates were found to be significantly higher in obese patients and both revision surgery and deep infection rates increased stepwise with increasing BMI levels.

Deep Infection rates were as follows: BMI<25 0%, BMI-25–30 1.3%, BMI-30–35 1.4%, BMI-35–40 3.2% and BMI>40 6.1%.

Revision rates were as follows: BMI<25 0%, BMI-25–30 0.9%, BMI-30–35 0.9%, BMI-35–40 3.2% and BMI>40 6.1%.

Although obese patients with knee osteoarthritis do benefit from joint arthroplasty, they suffer from an increased rate of complications and need for revision surgery.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_17 | Pages 29 - 29
1 Apr 2013
Lama P Spooner L St Joseph J Dolan P Harding I Adams M
Full Access

Introduction

Herniated disc tissue removed at surgery usually appears degenerated, and MRI often reveals degenerative changes in adjacent discs and vertebrae. This has fostered the belief that a disc must be degenerated before it can herniate, which has medicolegal significance. We hypothesise that degenerative changes in herniated disc tissues differ from those found in tissues that have degenerated in-situ, and are consistent with being consequences rather than causes of herniation.

Methods

Surgically-removed discs were examined using histology, immunohistochemistry and confocal microscopy. 21 samples of herniated tissues were compared with age-matched tissues excised from 11 patients whose discs had reached a similar Pfirrman grade of degeneration but without herniating. Degenerative changes were assessed separately in three tissue types (where present): nucleus, inner annulus, and outer annulus. Mann-Whitney U tests were used to compare ‘herniated’ vs ‘in-situ’ tissues.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXVIII | Pages 46 - 46
1 Jun 2012
Ker A Joseph J
Full Access

Due to working time restrictions a full-shift cross-covering system is commonplace. As more than one surgeon is responsible for trauma admissions in a 24-hour period a complete handover is paramount to ensure continuity of care.

The purpose of this audit was to determine whether the introduction of a formal handover/admission form would improve this continuity with regards to prescription of venous thromboembolism (VTE) prophylaxis in hip fracture patients.

In Stirling Royal Infirmary chemical VTE prophylaxis for hip fracture patients is 40mg enoxaparin at 6pm unless there is a contraindication. Over a 14-day period we prospectively documented the prescription of VTE prophylaxis and doses missed under the current admissions system. Following this a proforma was introduced that was to be exchanged at handover meetings. The proforma included patients' name/details, admission ward, and tasks to be completed during clerk-in, including VTE prophylaxis prescription. Tasks outstanding at handover had to be documented and completed by the subsequent doctor. Each form was signed and dated by the receiving doctor. We subsequently re-evaluated the prescription of VTE prophylaxis in hip fracture patients.

Between 1/12/10-15/12/10, 23 patients were admitted with hip fracture. 12 had appropriate VTE prophylaxis, 6 missed one dose, 4 missed two, and 1 missed three all due to failure of prescription.

Following the introduction of the proforma, 12 patients were admitted with hip fractures between 31/12/10-14/1/11. All were prescribed appropriate VTE prophylaxis and missed no doses. 1 patient was on warfarin and had enoxaparin prescribed but withheld until INR< 2.0.

After the introduction of a handover form VTE prophylaxis prescription vastly improved. This proforma ensured that all elements of initial management were completed allowing for physician accountability, greater efficacy of handover and continuity of care.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XI | Pages 16 - 16
1 Apr 2012
Joseph J Pillai A Ritchie D Mcduff E Mahendra A
Full Access

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign lesion of bone originally described by Nora et al in 1983. To date there are no UK-based case series in the literature. Here we present the Scottish Bone Tumour Registry (SBTR) experience of this rare lesion.

A retrospective analysis of SBTR records was performed. Histological specimens were re-examined by a consultant musculoskeletal oncology pathologist. Radiographs were re-reported by a consultant musculoskeletal radiologist. From 1983-2009, 13 cases were identified; 6 male, 7 female. Age ranged from 13-65. All patients presented with localised swelling. Pain was present in 5 and trauma in 2. 9 lesions affected the hand, 3 the foot, and 1 the tibial tuberosity. 12 lesions were excised and 1 curetted. There were 7 recurrences of which 6 were excised. 1 patients' recurrence was not treated. 1 lesion recurred a second time. This was excised. There were no metastases. Radiographs typically showed densely mineralised lesions contiguous with an uninvolved cortex. Cortical breakthrough was present in 1 case and scalloping in another. Histology characteristically showed hypercellular cartilage with pleomorphism and calcification/ossification without atypia; bone undergoing maturation; and a spindle-cell stroma.

SBTR records indicate that BPOP is a rare lesion with no sex predilection that affects patients over a wide age range. Minor antecedent trauma was present in only 2 cases. In agreement with Nora et al. we feel that trauma is unlikely to represent an aetiological factor. Recurrence was over 50% in this series. Although this is similar to that found in other reports, it may indicate that more extensive resection is required for this aggressive lesion. Finally, although radiological/histological findings are often bizarre there have been no reported metastases and so it is important that BPOP is not mistaken for, or treated as, a malignant process such as chondrosarcoma.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 301 - 301
1 Sep 2005
Courtenay B Neil M McGrath M M Joseph J Ma D
Full Access

Introduction and Aims: While clinical variables are considered important risk factors for post-arthroplasty VTE, the role of common genetic thrombophilic factors is less clear. The aims of this study were to determine if common thrombophilic genetic polymorphisms are independent risk factors for VTE post-arthroplasty; and if clinical variables are equally or more important.

Method: A prospective study of consecutive patients undergoing elective total hip or knee arthroplasty at a single institution, involving two surgeons. Patients were interviewed to assess clinical risks. Pre-operative blood samples were taken for Factor V Leiden (FVL), Pro-thrombin G20210A (PTH) and Methylenetetrahydrofolate reductase C677T (MTHFR) testing. All patients received routine enoxaparin prophylaxis and compression stockings. Intermittent pneumatic calf compression was also used by one surgeon. Presence of DVT was assessed using bilateral lower limb duplex ultrasonography (seven ± two days post-operatively) in all patients and performed in a vascular laboratory. Symptoms suggestive of pulmonary embolism were investigated by ventilation/perfusion lung scanning.

Results: A total of 569 patients were recruited with a median age of 67 years (range 20–90). Osteoarthritis was the main surgical indication. The overall incidence of post-operative venous thromboembolism (VTE) was 26%. Of thromboembolic events, 15% VTE were proximal DVT; 84% VTE were distal DVT and only one percent were pulmonary emboli. Prevalence of the thrombophilic genotypes was: 4.6% (heterozygous FVL mutation); 2.1% (heterozygous PTH); and 10.4% (homozygous C677T MTHFR mutation). Using univariate analysis, older age (p < 0.0005), total knee arthroplasty (p < 0.0005), recent surgery (p = 0.002), general anaesthesia (p = 0.013), operation time in minutes (p < 0.0005) and use of blood transfusions (p < 0.0005) were significantly associated with post-operative DVT. None of the thrombophilic genotypes were found to be significantly associated with post-operative DVT, however the frequency of FVL and PTH was highest in patients with proximal DVT and total hip arthroplasty patients with DVT. In multivariate analysis of both genetic and clinical thrombophilic factors, only age (p=0.02) and total knee arthroplasty (p< 0.0005) were found to be significant independent risk factors for post-operative VTE.

Conclusion: We conclude that clinical factors such as age and type of surgery (total knee arthroplasty) are independent risks for post-operative VTE in patients undergoing lower limb arthroplasty. FVL, PTH and MTHFR are not significant risk factors for post-operative VTE and screening for these mutations is not indicated.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_I | Pages 58 - 58
1 Jan 2003
Joseph J Raman R Macdonald DA
Full Access

The aim of revision hip arthroplasty for infection is to eradicate infection and restore function. There is, in current literature, little evidence to suggest an optimal time interval between first (excision) and second (reconstruction) stage procedures in revision hip arthroplasty.

Our aim was to assess the difference in outcome, in terms of patient pain, function and satisfaction, in relation to the time interval between surgeries.

A prospective analysis was made of 22 consecutive patients who underwent two-stage revision total hip replacement between 1992 and 2001. There were 12 male and 10 female patients. The mean age at the time of revision surgery was 63.5 years (range 35–83 years). The indication for surgery was infection in all cases. Patients were subdivided into two groups according to the time interval between first and second stages : Group 1 – time interval 6 months or less; Group 2 – time interval greater than 1 year. Outcome was assessed at 1 year post-operatively using change in pain and function scores and patient satisfaction scores.

Pre-operative pain and function scores were similar in the two Groups. Both Groups reported a similar improvement in pain at 1 year post-operatively. The patients in Group 1 also showed an improvement in function score, however, the patients in Group 2 showed no improvement in function. All patients felt the operation to be worthwhile as reflected in the patient satisfaction scores.

The results suggest that good improvements in pain can be achieved after short and longer time intervals. A longer time interval may well be associated with a poorer outcome in terms of restoring function.


The Journal of Bone & Joint Surgery British Volume
Vol. 49-B, Issue 4 | Pages 774 - 780
1 Nov 1967
Joseph J Watson R

1. Telemetering electromyography has been used to investigate the pattern of activity of certain muscles of the lower limb and back while the subjects walked up and down stairs.

2. During walking up and down stairs each limb has a supporting and swinging phase in each complete step.

3. Walking up stairs revealed the following facts. Firstly, raising the body on to the stair above is brought about by the contraction of the soleus, quadriceps femoris, hamstrings and gluteus maximus; the gluteus medius at the same time prevents the body falling on to the unsupported side. Secondly, the tibialis anterior dorsiflexes the foot during the swinging phase and helps the limb to clear the stair on which the supporting limb is placed. Thirdly, the hamstrings flex the leg at the knee in the early part of the swinging phase and control the terminal part of extension at the knee at the end of this phase. Fourthly, both erectores spinae contract twice in each step and control the forward bending of the body at the vertebral column.

4. Walking down stairs revealed the following. Firstly, the body is lowered on to the stair below by the controlled lengthening of the soleus and quadriceps femoris; the gluteus medius at the same time prevents the body from falling on to the unsupported side. Secondly, the tibialis anterior inverts the foot at the beginning of the supporting phase as the toe is placed on the stair below and dorsiflexes the foot in the middle of the swinging phase. Thirdly, the hamstrings control the extension of the leg at the knee during the middle of the swinging phase. Fourthly, both erectores spinae contract twice in each step and prevent forward bending of the trunk at the vertebral column.


The Journal of Bone & Joint Surgery British Volume
Vol. 36-B, Issue 3 | Pages 450 - 457
1 Aug 1954
Joseph J

1. The range of variation in the movements at the metatarso-phalangeal and interphalangeal joints of the big toe in fifty males has been investigated by means of lateral radiographs.

2. In the "neutral" position the proximal phalanx is dorsiflexed on the metatarsal and the distal phalanx dorsiflexed on the proximal. Sometimes the distal phalanx is plantar flexed on the proximal but this is not associated with any obvious abnormality of function.

3. There is a wide variation between individuals in the amount of movement found at these joints.

4. At the metatarso-phalangeal joint dorsiflexion is much more free than plantar flexion. The opposite is the case at the interphalangeal joint.

5. There is no significant difference between the right and left sides. Only in plantar flexion at both joints are there significant reductions in the range of movement in older age groups. These reductions are not functionally important.

6. There is an inverse relationship between active and passive dorsiflexion: the greater the range of active dorsiflexion, the less is the range of additional passive dorsiflexion.

7. In lateral radiographs the head of the metatarsal is always rounded.


The Journal of Bone & Joint Surgery British Volume
Vol. 31-B, Issue 4 | Pages 547 - 559
1 Nov 1949
Harris H Joseph J

1. The range of variation in full extension at the interphalangeal and metacarpo-phalangeal joints of the thumbs of 133 male and 100 female Europeans, and of 31 male Indians and 30 male Africans, has been investigated.

2. There is considerable variation between individuals in the maximum extension of both joints of the right and left thumbs in all groups studied.

3. The distribution for each joint in both thumbs in all groups is fairly symmetrical.

4. There is a high correlation between the right and left thumbs for both joints in all groups

5. The mean angle of extension at the right and left metacarpo-phalangeal joints in all groups is similar. Female Europeans, however, show a significantly greater mean angle than male Europeans.

6. The mean interphalangeal angle of extension in male Europeans is significantly greater than that in female Europeans and the mean in the Indian and African groups is significantly greater than in the male European group.

7. There is slight negative correlation between the metacarpo-phalangeal angle and interphalangeal angle in each thumb in the European groups.

8. Many subjects in all groups can increase extension at the metacarpo-phalangeal joint after flexing the carpo-metacarpal joint. Marked hyperextension (over 40°) is more frequent in the left than in the right thumb, in females than in males, and in male Indians than in male Europeans and Africans.

9. Maximum extension at the interphalangeal joints is not related to the presence of a sesamoid bone in the anterior part of the capsule of the joint.

10. The surfaces of the metacarpo-phalangeal joints vary considerably in shape. Those which are flat form about 10 per cent. of the sample and do not show hyperextension.

11. The factors influencing the amount of extension at the interphalangeal joint is the degree of laxity of the anterior capsule. The problem at the metacarpo-phalangeal joint is more complex; both the capsule and the shape of the joint surfaces play important roles.