Pigmented villonodular synovitis (PVNS) is a rare benign disease of the synovium of joints and tendon sheaths, which may be locally aggressive. We present 18 patients with diffuse-type PVNS of the foot and ankle followed for a mean of 5.1 years (2 to 11.8). There were seven men and 11 women, with a mean age of 42 years (18 to 73). A total of 13 patients underwent open or arthroscopic synovectomy, without post-operative radiotherapy. One had surgery at the referring unit before presentation with residual tibiotalar PVNS. The four patients who were managed non-operatively remain symptomatically controlled and under clinical and radiological surveillance. At final follow-up the mean Musculoskeletal Tumour Society score was 93.8% (95% confidence interval (CI) 85 to 100), the mean Toronto Extremity Salvage Score was 92 (95% CI 82 to 100) and the mean American Academy of Orthopaedic Surgeons foot and ankle score was 89 (95% CI 79 to 100). The lesion in the patient with residual PVNS resolved radiologically without further intervention six years after surgery. Targeted synovectomy without adjuvant radiotherapy can result in excellent outcomes, without recurrence. Asymptomatic patients can be successfully managed non-operatively. This is the first series to report clinical outcome scores for patients with diffuse-type PVNS of the foot and ankle. Cite this article: Bone Joint J 2013;95-B:384–90

Aims

The primary objective was to determine the incidence of COVID-19 infection and 30-day mortality in patients undergoing foot and ankle surgery during the global pandemic. Secondary objectives were to determine if there was a change in infection and complication profile with changes introduced in practice.

Introduction. Osteoarthritis commonly affects the first metatarsophalangeal joint. Stress across this joint has been postulated to increase the incidence of osteoarthritis. Certain foot structures have been associated with a higher incidence of osteoarthritis of the big toe. Utilizing finite elemental analysis, bone stress across the first metatarsophalangeal joint was calculated during mid stance phase of gait and compared in different foot structures. Method. A geometrically accurate three dimensional model of the first metatarsophalangeal joint was created utilising a high resolution 7 tesla MRI and Mimics v14 imaging software. Planus, rectus and cavus feet were simulated by varying the metatarsophalangeal declination angle to 10.1, 20.2 and 30.7 degrees, respectively. A non-manfold computer aided design technique in Mimics v14.2 and finite element method in ANSYS v12 FE were utilised to create the boundary conditions, representing the double support stance phase of gait. Using information from 61 asymptomatic patients with different foot types walking over a Novel emed-x plantar pressure measuring system, plantar loading conditions were applied. Finite elemental analysis was used to predict stress in the first metatarsophalangeal joint in the different foot types. Results. The peak stresses in the distal first metatarsophalangeal joint cartilage were 1.1×10(6) Pa, 6.0×10(5) Pa and 9.7×10(5) Pa for planus, rectus and cavus foot types, respectively. This corresponds to 83.3 percent and 61.6 percent increases in first metatarsophalangeal joint contact stress for the planus and cavus feet relative to the rectus foot. Conclusion. The results suggest there is a higher contact stress of the first metatarsophalangeal joint in patients with pes planus and pes cavus compared to the rectus foot. This may account for the increase risk of first metatarsophalangeal joint osteoarthritis in patients with pes planus. Further work has been initiated utilising this model to measure first metatarsophalangeal joint stress with different hindfoot loading

Introduction. Morton's Neuroma is routinely treated by excision of the interdigital nerve. Traditional surgery works by denervation, but the results are variable, and recurrence is common. Multiple Morton's Neuromas present a difficult clinical challenge. MR and ultrasound often demonstrate a normal nerve or an interdigital bursa. Some experts advise division of the intermetatarsal ligament rather than excision. This case series evaluates an alternative method of treatment. Methods. Patients with a clinical diagnosis of Morton's Neuroma, with symptoms only on weight bearing, were treated with division of the intermetatarsal ligaments and Weil's osteotomies. The nerve was not excised. Patients wore a postoperative shoe for six weeks. If radiographs were satisfactory, they returned to weight bearing in a normal shoe. They were evaluated at 12 weeks with AOFAS scoring, as part of the routine clinical pathway. Results. 14 patients were treated with Weil's osteotomy, including one who had recurrence of symptoms following traditional surgery. The mean AOFAS score rose from 71 to 91. No patient had recurrent symptoms after surgery. The patient who had previously been treated with excision of the nerve also had some improvement. Discussion. The success of this surgery in relief of symptoms in this case series raises questions about the pathology, diagnosis and treatment of Morton's Neuroma. Many MR studies find abnormal nerves in asymptomatic patients, and no neuroma in symptomatic patients. Patients have symptoms exacerbated by weight bearing, and nerve compression may play an important part in the pathophysiology. Weil's osteotomy works by decreasing the effective weight bearing in the involved rays. It is particularly useful if symptoms exist in multiple intermetatarsal areas. Conclusions. Multiple Weil's osteotomies are an effective method for treatment of Morton's Neuroma. The basis for the traditional approach of excision of the nerve may be flawed and merits further study

Aims

Preoperative talar valgus deformity ≥ 15° is considered a contraindication for total ankle arthroplasty (TAA). We compared operative procedures and clinical outcomes of TAA in patients with talar valgus deformity ≥ 15° and < 15°.

Introduction. Periprosthetic cyst formation following ankle replacement, requiring revision surgery, has previously been reported. The exact pathogenesis of cyst formation is unclear but considered to be due to a combination of biological and mechanical factors. Our objective was to review the incidence of periprosthetic cyst formation following Mobility ankle replacement and their outcome. Patients and methods. We reviewed all the Mobility ankle replacements performed by the senior author from Oct 2005 till May 2012. Serial radiographs were reviewed to identify the presence of cystic lesions in the tibia or the talus. Results. 124 Mobility ankle replacements were performed in 116 patients during our study period. Average age was 65 years (22 to 88) with male to female ratio of 2:1. Average follow-up was 32 months (7 to 73). Radiographic review of the most recent available radiograph showed cystic changes in the distal tibia in 10 patients (8%). One patient had cystic appearance pre-operatively which was not found to be progressive after replacement. Seven patients were asymptomatic. Three patients presented with ankle pain, which was thought to be due the cyst. One of the symptomatic patients had undergone revision of tibial component and bone grafting of the cyst 32 months after primary surgery. The second patient is awaiting surgery for exploration and possible bone graft (40 months after primary surgery). The 3. rd. patient is awaiting CT scan for further evaluation of the cyst. Conclusion. Our study shows that cystic changes were present in 8% of TAR at medium term review. 70% (7 patients) were asymptomatic and 30% required intervention for being symptomatic. Regular review of the TAR patients is essential to identify the patients who develop cyst formation

The aim of this study was to identify the incidence of post-operative symptomatic deep-vein thrombosis (DVT), as well as the risk factors for and location of DVT, in 665 patients (701 ankles) who underwent primary total ankle replacement. All patients received low-molecular-weight heparin prophylaxis. A total of 26 patients (3.9%, 26 ankles) had a symptomatic DVT, diagnosed by experienced radiologists using colour Doppler ultrasound. Most thrombi (22 patients, 84.6%) were localised distally in the operated limb. Using a logistic multiple regression model we identified obesity, a previous venous thromboembolic event and the absence of full post-operative weight-bearing as independent risk factors for developing a symptomatic DVT.

The incidence of symptomatic DVT after total ankle replacement and use of low-molecular-weight heparin is comparable with that in patients undergoing total knee or hip replacement.

We reviewed 91 patients (103 feet) who underwent a Ludloff osteotomy combined with additional procedures. According to the combined procedures performed, patients were divided into Group I (31 feet; first web space release), Group II (35 feet; Akin osteotomy and trans-articular release), or Group III (37 feet; Akin osteotomy, supplementary axial Kirschner (K-) wire fixation, and trans-articular release). Each group was then further subdivided into severe and moderate deformities.

The mean hallux valgus angle correction of Group II was significantly greater than that of Group I (p = 0.001). The mean intermetatarsal angle correction of Group III was significantly greater than that of Group II (p < 0.001). In severe deformities, post-operative incongruity of the first metatarsophalangeal joint was least common in Group I (p = 0.026). Akin osteotomy significantly increased correction of the hallux valgus angle, while a supplementary K-wire significantly reduced the later loss of intermetatarsal angle correction. First web space release can be recommended for severe deformity. Additionally, K-wire fixation (odds ratio (OR) 5.05 (95% confidence interval (CI) 1.21 to 24.39); p = 0.032) and the pre-operative hallux valgus angle (OR 2.20 (95% CI 1.11 to 4.73); p = 0.001) were shown to be factors affecting recurrence of hallux valgus after Ludloff osteotomy.

Cite this article: Bone Joint J 2013;95-B:803–8.