Tendoscopy in the treatment of peroneal tendon disorders is becoming an increasingly safe, reliable, and reproducible technique. Peroneal tendoscopy can be used as both an isolated procedure and as an adjacent procedure with other surgical techniques. The aim of our study was to review all peroneal tendoscopy that was undertaken at the AOC, by the senior authors (IGW, SH), and to determine the safety and efficacy of this surgical technique.

Fifth metatarsal fractures in sport are known to be associated with acceleration and cross cutting movements when running. It is also established that playing surface has an impact on the ground reaction forces through the foot, increasing the strain through the fifth metatarsal. But what impact does boot design have on these forces? Current thought is that boots that utilise a blade stud design resist sideways slipping of the planted foot more than boots with a rounded stud. This study aims to compare ground reaction forces through the fifth metatarsal in 2 two different designs of rugby boot to assess what impact stud design might have. The forces across the foot were measured using Tekscan in-shoe pressure plates in 24 rugby players. Each player was asked to complete an agility course to measure acceleration, cutting and cross-cutting in the two different designs of rugby boot, reproducing true playing conditions. The boots used were the Canterbury Phoenix Club 8 Stud boot and the Canterbury Speed Club Blade boot. The trial was conducted on an 4G artificial pitch at the Cardiff Arms Park rugby ground. Ethical approval was obtained from Bath University and a research grant was provided by British Orthopaedic Foot and Ankle Society. The blade boot had significantly higher contact pressures than the stud boot on the fifth metatarsal in the combined movements (17.909 ± 10.442 N/cm2 Blade Vs 16.888 ± 9.992 N/cm2 Boot; P < .0125; n= 864 steps in each boot group). The blade boot also produced higher pressure during cross-cutting (32.331 ± 13.568 N/cm2 Vs 27.651 ± 15.194 N/cm2 p < 0.007). Pressures were also higher in both acceleration and cutting, although not significantly so. These results will guide clinicians advising athletes in shoe design, especially those predisposed to or rehabilitating from a fifth metatarsal fracture.

Background

Total ankle replacements (TARs) are becoming increasingly more common in the treatment of end stage ankle arthritis. As a consequence, more patients are presenting with the complex situation of the failing TAR. The aim of this study was to present our case series of isolated ankle fusions post failed TAR using a spinal cage construct and anterior plating technique.

Introduction

Talus fractures have traditionally been reported as having poor outcomes with rates of avascular necrosis in excess of 80% in some studies. It was noted by the senior author that this was not his experience in a tertiary institution with many patients having good to excellent outcomes and lower rates of avascular necrosis than anticipated despite high-energy trauma. The aim of this paper is to review all talus fractures that have been fixed internally at our institution to determine whether current surgical techniques have improved traditionally poor outcomes. This could result in improved outlook for patients on initial presentation and improved ability to manage the long-term consequences of the multiply-injured patient.

Introduction

Flexor Hallucis Longus (FHL) tendon transfer is a well-recognised salvage operation for irreparable tendon Achilles (TA) ruptures and intractable Achilles tenonopathy. Several case series describes the technique and results of arthroscopic FHL tendon transfers. We present a comparative case series of open and arthroscopic FHL tendon transfers from Southmead Hospital, Bristol, UK.

Introduction

Arthroscopic ankle fusion is an effective treatment for end stage ankle arthritis. It reliably improves pain but at the expense of ankle motion. Development of adjacent degenerative joint disease in the foot is thought to be a consequence of ankle fusion due to altered biomechanics. However, it has been reported to be present on pre-operative radiographs in many patients. There is very little evidence reporting the long-term outcomes of patients undergoing arthroscopic ankle fusion and particularly those requiring secondary procedures for adjacent joint disease.

The Zenith^TM total ankle replacement (Corin, Cirencester) is a mobile-bearing implant based on the Buechal Pappas design. Key features are the simple fully-jigged instrumentation aiming to improve accuracy and reproducibility of implant positioning, cementless calcium phosphate coated surfaces for improved early osseointegration, and titanium nitride-coated bearing surfaces to resist wear. We present early to mid-term survival data for 155 total ankle replacements implanted by three surgeons in our institute.

Case records of all patients undergoing Zenith^TM Total Ankle Replacement by three senior surgeons, including a member of the design team, between 2007 and 2014 were examined. Patients were examined clinically and radiographically annually after the early postoperative period. The primary outcome measure was implant survival. Secondary outcome measures included complication rates, parameters of radiographic alignment, and radiographic evidence of cysts and loosening.

One hundred and fifty-five cases were performed for a mixture of primary pathologies, predominantly primary or posttraumatic arthrosis. Mean follow-up was 50 months. Implant survival was 99.0% at 3 years (n=103), 94.0% at 5 years (n=50), and 93.8% at 7 years (n=16). One patient was revised to arthrodesis for aseptic loosening, one arthrodesis was performed for periprosthetic infection with loosening, and one below-knee amputation was performed for chronic pain. Three cases underwent further surgery to address cysts, and 7 malleolar fractures were reported. Medial gutter pain was experienced by 9% of patients.

Overall, our data show excellent early and mid-term survivorship for the Zenith^TM Total Ankle Replacement. Simple fully-jigged instrumentation allows accurate and reproducible implant alignment.

Aim:

Ankle sprains are one of the most common sports injuries. Around 10–20 % of the acute ankle sprains may lead to the sequelae of chronic ankle instability. Around 15–35% of the patients have residual pain following successful lateral ligament reconstruction. One of the reasons suggested for the persistent symptoms following lateral ligament reconstruction has been the presence of intra-articular pathology.

Introduction:

Symptomatic tarsal coalitions failing conservative treatment are traditionally managed by open resection. Arthroscopic excision of calcaneonavicular bars have previously been described as has a technique for excising talocalcaneal bars using an arthroscope to guide an open resection. We describe a purely arthroscopic technique for excising talocalcaneal coalitions. We present a retrospective two-surgeon case series of the first eight patients (nine feet).

Symptomatic tarsal coalitions failing conservative treatment are traditionally managed by open resection. Arthroscopic excision of calcaneonavicular bars have previously been described as has a technique for excising talocalcaneal bars using an arthroscope to guide an open resection. We describe an entirely arthroscopic technique for excising talocalcaneal coalitions and present a retrospective two-surgeon case series of the first eight patients (nine feet).

Outcome measures include restoration of subtalar movements, return to work and sports, visual analogue pain scales and Sports Athlete Foot and Ankle Scores (SAFAS). Follow-up ranges from 1 year to 5.5 years.

Subtalar movements were improved in all feet. Deformity was not always fully corrected but pain and SAFAS scores improved in all patients bar one. They all had a rapid return to good function apart from this same patient who required subsequent fusions. The posterior tibial nerve was damaged in one patient.

Minimal destruction of bone and soft tissues allows early mobilization and minimizes pain. We acknowledge the risk of neurological damage from any operative technique. Patient selection and preoperative planning are crucial. This series from two independent surgeons supports the feasibility and effectiveness of this technique.

Osteochondral lesions (OCL) of the talus occur in 38% of the patients with supination external rotation type IV ankle fractures and 6 % of ankle sprains. Osteoarthritis is reported subsequently in 8–48% of the ankles. Several marrow stimulation methods have been used to treat the symptomatic lesion, including arthroscopic debridement and micro fracture. Encouraging midterm results have been reported, but longterm outcome is unknown in relation to more invasive treatments such as transfer of autologous osteoarticular tissue from the knee or talus (OATS), autologous chondrocyte implantation (ACI), frozen and fresh allograft transplantation.

The relationship between hindfoot and forefoot kinematics is an important factor in the planning of ankle arthrodesis and ankle arthroplasty surgery. As more severe ankle deformities are corrected, improved techniques are required to assess and plan hindfoot to forefoot balancing.

Gait analysis has previously been reported in patients with ankle arthritis without deformity. This group of patients have reduced intersegment motion in all measured angles. We have looked at a small group of patients with hindfoot deformity and ankle arthritis awaiting fusion or replacement.

Using the Oxford Foot Model we have assessed lower limb kinematics with a focus on hindfoot to forefoot relationships. The results of our pilot study are in variance to previous studies in that we have shown that in the presence of hindfoot/ankle deformity, the forefoot range of motion increases. We feel that these data may impact on surgical planning.

Background

Many scoring systems exist that assess ankle function, none of them are validated for use in a group of higher demand patients. This group of patients there have potential problems with ceiling effects, not being able to detect change or that a sports-subscale is not included. This study was to create a validated self-administered scoring system for ankle injuries in athletes by studying existing scoring systems and key-informant interviews.

Background

Traditional measurements of hindfoot alignment are based on the tibio-calcaneal angle and do not take the forefoot into account. We have developed an algorithm based on standard radiographs to calculate calcaneal offset using Ground Reaction Force (GRF).

The diagnosis of Osteochondral Chondral Lesion of the talar dome is ever more regularly made. Though algorithms of management have emerged by recognising the position, size and the most reliable treatment options, the problem of the failed or relapsed case has only been considered in limited publications.

When considering the failed case a variety of possibilities have to be considered.

The characteristics of the patient have to be considered. The nature of the original presentation and the history of the present as opposed to the past compliant are worth noting. Patients who have no history of trauma do seem to have a different natural history and response to treatment. The young and the old may well respond differently.

Factors preventing recovery from surgery such as ongoing instability of the ankle or hindfoot deformity creating on going abnormal pressures on the joint surface should be looked for.

The possibility that the surgery undertreated or missed the full nature of the lesion has to be considered. The possibility of an untreated further pathology should be reviewed.

The severity of the original lesion and it's likely response to treatment should be considered. Larger cystic lesions would be more likely to have a poorer outcome. Ultimately if there are persistent symptoms and evidence of ongoing unresolved pathology on the joint surface alternative techniques to resurface the joint should be considered.

Hind and mid foot arthritis is often noted in patients who have previously had an ankle arthrodesis. It has been suggested that this arthritis may be precipitated or exacerbated as a direct result of the ankle fusion. The aim of this study was to investigate the degree and pattern of pre-existing ipsilateral foot arthritis in patients who have subsequently undergone ankle arthrodesis.

A retrospective review of the most recent pre-operative radiographs of 70 patients who underwent 71 arthrodeses between 1993-2003 was performed. Patients with rheumatoid disease were excluded. The immediate pre-operative AP and lateral ankle radiographs were assessed and the presence and severity of osteoarthritis for the sub-talar, talo-navicular, naviculo-cuneiform and calcaneo-cuboid joints was recorded using the Kellgren and Lawrence grading score. This was performed simultaneously by two reviewers and a consensus obtained. A total score out of 16 was given for each radiograph.

68 (96%) of the radiographs reviewed showed evidence of pre-existing hind or mid foot arthritis prior to ankle fusion. The sub-talar joint was the most commonly and severely affected. The median total arthritis score for each radiograph was 5. There was no association between age or causative pathology and the degree of arthritis.

This study has demonstrated that hind and mid foot arthritis is very common in patients with co-existent ankle arthritis prior to ankle fusion. This has previously been assumed to have developed as a result of the surgery but is, in fact, present at the time of the operation and this needs to be taken into consideration when evaluating the results of ankle arthrodesis

Simultaneous arthrodesis of the ankle and subtalar joints is an established treatment option for combined ankle and subtalar arthritis or complex hindfoot deformities. The use of a curved intra medullary nail has potential advantages in terms of stability, hindfoot alignment and avoidance of the lateral neurovascular bundle.

We devised a comparative description of the results of hindfoot fusion using a curved locking nail before and after the introduction of anatomically specific modifications to the device through a retrospective review of notes and radiographs of patients undergoing simultaneous ankle and subtalar fusion by retrograde intramedullary nailing using an ACE¯ (Humeral Nail. Patients undergoing the same procedure using the Tibiotalocalcaneal [TTC] Nail System [DePuy] were recruited and studied prospectively. The outcome was assessed by a combination of notes review, clinical examination and telephone questionnaire.

Between 1996 and 2004, 71 arthrodeses in 67 patients have been performed. The average follow up is 27 months [3-73] and mean age 58 years. Fifty-two arthrodeses utilised the ACE humeral nail and nineteen used the newer TTC nail. Both nailing systems are locked proximally and distally and provide a short radius laterally directed distal curve. Mean time to union is 4.3 months [3-10]. Average AOFAS hindfoot score post-operatively is 65, with a mean improvement of 40 points from the pre-operative score in the TTC nail group. Post-operative complications included deep infection, amputation and a non-union rate of 10% overall. In the humeral nail group, four symptomatic stress reactions [8%] and three fractures of the tibia [6%] occurred at the tip of the nail. No stress-riser effect has to date been seen in the TTC nail group. Prominent metalwork removal has also been significantly reduced in the TTC nail group.

Our results show hindfoot fusion using a curved intramedullary nail to be an effective technique in complex cases of hindfoot arthritis and deformity. Anatomically specific alterations to the nail have resulted in a significant reduction in certain complications. Alternate proximal locking options in the TTC nail have reduced prominent metalwork and, more significantly, the incidence of stress reactions and fractures appears to have been eliminated.

Introduction: Non-union following hindfoot arthrodesis remains a significant risk in foot and ankle surgery. In the reported series of revision hindfoot arthrodeses non-union rates range from 9 to 25% with approximately half these patients going on to a transtibial amputation. Bone morphogenic proteins (BMP) are a group of naturally occurring proteins with strong osteoinductive properties, which have shown promise in the treatment of fracture non-unions and primary hindfoot arthrodesis surgery. This article reports our experiences with rhBMP-7 as an adjunct to revision arthrodesis surgery in this high-risk subset of patients.

Methods: Eight patients with at least one previous non-union and two or more risk factors for non-union and one patient on steroids with a failed total ankle replacement were prospectively recruited to the study. A revision arthrodesis procedure with internal fixation was performed according to the senior author’s revision protocol with the addition of 3.5mg rhBMP-7 combined with 40mls of bone marrow aspirate. Bone graft was used only if there was structural bone loss. Outcome was assessed clinically and radiologically.

Results: Follow-up ranges from 3 to 22 months (average 13 months). Clinically 8 of the 9 patients had a pain free, stable arthrodesis. Seven patients were satisfied with their functional improvement and pain relief. Radiologically two patients have united, six patients have partial unions with ongoing progression towards union and one patient has a painless non-union. There was one wound infection and one malunion. No complications related to rhBMP-7 were experienced.

Conclusion: Revision arthrodesis with adjuvant rhBMP-7 has led to limb salvage in this group of high-risk patients. However, rhBMP-7 is not a panacea for achieving union and does not replace meticulous surgical planning and technique. Achieving bony union in this subset of patients remains a high risk and protracted process. No concerns about the short-term safety of rhBMP-7 were raised.

Introduction: Fresh autogenous cancellous bone graft is the material of choice in reconstruction and fusion procedures in foot and ankle surgery. There are many potential donor sites for graft harvest, all with recognised minor and major complications. The proximal tibia is one such potential site, and is particularly suited to foot and ankle surgery being within the operative field and under tourniquet control.

Purpose: To assess pain, morbidity and ability to weight bear in a large group of patients undergoing foot and ankle surgery utilising cancellous bone graft from the proximal tibia.

Method: A retrospective audit was undertaken of 148 procedures performed over a period of five years. Minimum follow-up was 3 months. Data were obtained from operation notes and patient interview.

Results: Most patients had no pain (78%) or very mild pain (20%) at the site of graft harvest immediately following surgery. At review, 96% had no pain; 4% had very mild pain with certain activities such as kneeling. There were no major complications. 4 patients (2.7%) had persisting areas of parasthaesia at review, but none were troubled by it. One patient had a superficial wound problem that resolved. The ability to bear weight was dictated by the primary procedure. Usually this was from 2–3 weeks. There were no complications related to early weight bearing in this series.

Conclusion: The proximal tibia is a suitable and safe site for bone graft harvest for foot and ankle surgery. There is no need for additional restriction in weight bearing following this procedure.

Introduction: Osteochondral lesions of the Talar Dome(OCD) remain a difficult therapeutic problem. One solution has been to consider using autologous chondrocyte implants. Though initial results of this technique are interesting the donor sites have always been in a normal knee. The presence of knee symptoms subsequently in some patients might be regarded as inevitable. This paper reports on the viabilty of donor material taken from the ankle.

Materials: Twenty four patients have been recruited to a pilot study of the viability of obtaining donated chondral material for Matrix Autologous Condrocyte Implantation. There were 14 men and 10 women. Their mean age was 37.3 years (range 17–63). All were complaining of presistent symptoms of pain and some insecurity following previous conventional surgery for treatment of a symptomatic OCD. All had MRI evidence of ongoing changes in keeping with persistent problems related to an OCD.

Methods: All patients had an initial arthroscopy of the affected ankle to reassess the state of the joint surface. Donor articular cartilage was obtained from one of three sites. The anterior part of the joint surface on the talar neck, from the medial articular facet of the talus or rarely from an area of articular cartilage on the edge of the lesion. The mean weight of the donor harvest was 133 micrograms(range51–450).

Results: All donated graft material produced viable implantable graft material between 5 and 7 weeks from harvest. Cell counts ranged from 12.3 million to 20 million with cell viabilities of 98% or above. These figures are directly comparable with the results obtained from the knee despite the original donor weights being less.

Conclusion: If this technique is contemplated the use of the affected ankle as a donor site is a viable alternative to the knee.

Morton’s syndrome is an entrapment of a digital nerve between the metatarsal heads in the foot causing pain between the metatarsal heads. 41 subjects with signs and symptoms of Morton’s syndrome were prospectively examined with an ultrasound scan and the size of the bifurcation of the interdigital nerve was recorded if it was visible. Each subject completed a Visual Analogue Scale and short form McGill Pain Questionaire before an injection of local anaesthetic and corticosteroid was administered. The subjects were reviewed after 6 weeks and the pain scores repeated.

26 subjects had positive ultrasounds with a mean width of 5.1 mm, range 2.7–9.8 mm and 15 subjects had negative ultrasounds. Differences in mean ranks of VAS scores between the two groups were borderline statistically significant for scores before injection (p=0.064). Difference in mean rank of VAS score was significant after injection (p=0.013).

Differences in mean ranks of MPQ scores were borderline statistically significant for changes in scores (p=0.062). Difference in mean rank of MPQ score was significant after injection (p=0.007). None of the correlations between nerve width and any of VAS or MPQ outcome measures were statistically significant.

This study demonstrates that the larger the neuroma on the ultrasound, the more painful it is for the patient. This study suggests that patients who have a small or absent neuroma demonstrated on the ultrasound scan are more likely to have their pain reduced to an acceptable level with an injection of local anaesthetic and corticosteroid than those patients with a large neuroma. Ultrasound examination is a useful tool in the management of patients with Morton’s syndrome.

Aim: A medium term review of total ankle replacements with a view to reviewing follow up protocols, reassessing the usefulness of the SF12 Health Survey questionnaire, and to determine factors that may indicate early failure.

Method: Sixty-five ankle replacements in 58 patients with an average age at operation of 65 (44–80) (32 males: 23 females, 3 died) were reviewed after a mean of 41 months (8–97 months). They were assessed via postal questionnaire and a research clinic with regard to their pain, difficulty and SF 12 scores, their outcome perception and range of movement. Additionally, we looked retrospectively at their notes and latest X-rays.

Results: Indications for operation were OA (79.5%), RA (18.2%) and psoriatic arthropathy (2.3%). Patients’ perceptions of their outcomes were 41(78.8%) good, 5(9.6%) moderate and 6(11.5%) poor. The average “mean pain score” was 3.6 and average “mean difficulty score “ was 4.0. There was no significant change between the pre and post-operative mean SF 12 scores. Save for 2 anomalies, poor outcomes and SF12 scores were only seen in post-traumatic OA(100%) and RA patients. Prostheses used were Beuchel-Pappas, OSG and DePuy Mobility. There are no revisions to date. The average range of movement was 26°. X-rays generally showed good prosthesis alignment, minimal insert wear, occasional non-enlarging, small (1–2mm) cysts around the tibial component.

Conclusions: The SF 12 scores seem to be unresponsive. The pain and difficulty scores more reflect the patients’ perception of outcome. With the low incidence of revision, risk factors for early failure are difficult to establish but patients with radiological cysts, talar collapse or more severe deformities of the foot/ankle might be the ones who need regular review.

Aim: To report the clinical and radiological results of patients undergoing hindfoot fusion using an intramedullary nail. Methods: Retrospective review of notes of patients undergoing combined ankle and subtalar arthrodesis using retrograde intramedullary nailing. The procedure is performed mainly for the treatment of complex hindfoot deformities or following failed total ankle arthroplasty. Outcome was assessed by notes review, clinical examination and telephone questionnaire. Results: Between 1995 and 2001 56 arthrodeses in 52 patients have been performed. The average follow up is 3 years. Approach to the joints was via an anterolateral incision unless previous surgery dictated otherwise. All cases utilised an ACE¨ humeral nail which was locked proximally and distally. Most procedures utilised bone graft from the þbula, proximal tibia, iliac crest or allograft femoral head. Mean tourniquet time was 114 mins. Post-operative management generally consisted of 3 months plaster immobilisation. Post-operative complications included deep infection, amputation, stress fracture, non-union & prominent metalwork. At review 90% of patients were satisþed and approximately 90% felt the pain level & function of their foot had improved. Average postoperative AOFAS hindfoot score was 65. Conclusion: Hindfoot fusion by intramedullary nailing is an effective technique in complex cases of deformity and in many cases is the only alternative to amputation. Patient satisfaction appears to be high but the procedure is demanding and the complication rate can be signiþcant.

Aim

To report the clinical and radiological results of patients undergoing hindfoot fusion using an intramedullary nail.

Methods

Retrospective review of notes and radiographs of the patients of 2 surgeons who perform combined ankle and subtalar arthrodesis using retrograde intramedullary nailing with an ACE® humeral nail. The procedure is performed mainly for the treatment of combined ankle and subtalar arthritis or complex hindfoot deformities. Outcome was assessed by a combination of notes review, clinical examination and telephone questionnaire.

Results

Between 1995 and 2001 54 arthrodeses in 51 patients have been performed. The average follow up is 3 years. Approach to the joints was via a vertical anterolateral incision unless previous surgery dictated otherwise. All cases utilised an ACE® humeral nail which was locked proximally and distally. Most procedures utilised bone graft from the fibula, proximal tibia, iliac crest or allograft femoral head. Mean tourniquet time was 122 mins. Intra operative complications included one fractured tibia and one fractured medial malleolus. Postoperative management generally consisted of 3 months plaster immobilisation. Only 3 cases were immobilised significantly longer than this. Postoperative complications included deep infection, amputation, stress fracture, non-union & prominent metalwork. At review almost 78% of patients were satisfied with the results of surgery and approximately 80% felt the pain level & function of their foot had improved. Average postoperative AOFAS hindfoot score was 73.

Conclusion

Hindfoot fusion by intramedullary nailing is an effective technique in complex cases of deformity and in many cases is the only alternative to amputation. Patient satisfaction appears to be high but the procedure is demanding and the complication rate can be significant.

Aim

To assess the results of arthroscopic treatment of osteochondral lesions of the talus and identify factors associated with a poor outcome.

Materials and Methods

Sixty patients (44 male, 16 female) with an average age at operation of 34 years(14 to 72 years) were reviewed after an average of 42 months(6 to 99 months). Patients were graded according to the criteria of Berndt and Harty1. Pre-operative radiographs and MRIs were graded according to Anderson et al2 and Hepple et al3 respectively. Forty-one lesions were medial, 31 of which were traumatic and 19 were lateral, all of which were traumatic. Thirty-four patients were treated with excision and curettage, 22 by excision and drilling, 2 by internal fixation and 2 by bone grafting.

Results

Thirty-one patients achieved a good outcome, 16 fair and 13 poor. Of the 13 poor results, 12 were medial lesions. Medial lesions presented later than lateral lesions (three years compared with 18 months) and almost 50% demonstrated cystic change on radiographs and MRI whereas only one lateral lesion demonstrated such changes. Outcome was not associated with patient age and no difference was found between traumatic and atraumatic medial lesions.

Conclusion

Most osteochondral lesions are well served by conventional treatment. However cystic lesions, usually of the medial aspect of the talus, do represent a therapeutic challenge.

Postoperative anterior knee pain was evaluated in a consecutive series of 138 knees in 108 patients with rheumatoid arthritis treated by total knee replacement with Mark I Insall-Burstein prostheses. No knee had primary patellar resurfacing, and in the 119 knees followed up for a mean of 63.9 months, none had secondary resurfacing. Anterior knee pain was absent in 87 knees (73%), mild in 16 (13.5%) and moderate or severe in 16 (13.5%). The height of the patella above the prosthetic joint line was the only variable which was directly related to the incidence of anterior knee pain. The sensitivity and specificity of patellar height measurements for identifying patients with or without pain were derived. From these data, a selective policy of resurfacing the patella in those at risk was adopted. Choosing a patellar height of 15 mm or less, patellar resurfacing could be avoided in 80% of patients likely to have no pain, and the patella could be resurfaced in 65% of those likely to have anterior knee pain.