Background

Total ankle arthroplasty is an accepted alternative to arthrodesis of the ankle. However, complication and failure rates remain high compared to knee and hip arthroplasty. Long-term results of the Scandinavian Total Ankle Replacement (STAR) are limited, with variable complication and failure rates observed. This prospective study presents the long-term survivorship and the postoperative complications of the STAR prosthesis. Additionally, clinical outcomes and radiographic appearance were evaluated.

Background

Ankle arthroplasty is increasingly used to reduce pain and improve or maintain joint mobility in end-stage ankle arthritis. Both treatments show similar results with regard to functional outcome scores and sport related activities. However, the rates of complications and reoperations were higher after ankle replacement. Particularly for the first implant designs, with more promising results for newer designs.

One of these newer designs is the Mobility Total Ankle System. Short term results in recent literature describe an improvement of functional outcomes; however complication rates vary widely, ranging from 9 to 37% and the 4-year survival rates ranging between 84 and 98 percent. Therefore, the aim of this study was to assess the clinical and radiographic short term results of the Mobility prosthesis.

Introduction: Total ankle prostheses (TAP’s) are implanted for end stage cartilage damage especially in patients with rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA) or post-traumatic arthritis. Little is known about the long term survival of these prostheses in patients with RA and JIA. In this study we examined the outcome of TAP in these patients.

Patients and methods: Between 1994 and 2004 85 TAP’s were implanted in 58 cases (10 males and 48 females) with RA (n=53) or juvenile chronic arthritis (n=5). The records of all patients were reviewed. Every patient was invited for a visit to our outpatient clinic for a history taking, a physical examination and a Kofoed ankle score (a clinical score for ankle function ranging from 0 to 100) was obtained.

Results: The record of every patient was available for review. Two patients had died (cause of death was unrelated to the surgery), and 56 patients could be reexamined. A perioperative fracture (8 medial 3 lateral and 2 tibial) occurred in 13 cases. The fractures were fixed in the same operation and healed without complications; none of these prostheses needed a reintervention. After a mean follow up of 2.7 years (range 1 to 9 years) two patients died with the prosthesis in situ, one patient underwent an above knee amputation for infected arthroplasties of ankle and knee and four prostheses were removed because of loosening or malfunctioning of the prosthesis and arthrodeses were performed. The other 51 cases were analysed and showed a mean Kofoed ankle score of 72.8 (SD=15.8). This score is similar to scores obtained from patients receiving ankle arthroplasties for non-rheumatic indications.

Conclusions: Placement of total ankle prostheses in patients with RA shows good medium term results. The intra-operative fracture rate is high, but does not affect the outcome; none of the failed arthroplasties was due to a preoperative fracture.

Introduction: The standard procedure when operating the rheumatoid forefoot is resection arthroplasty of the metatarsophalangeal joints of the lesser rays. Correction of the hallux is mostly achieved by arthrodesis of the first metatarsophalangeal joint. Good clinical results (with a follow-up of over ten years) have been reported when a combination of these two techniques is used. Another technique is repositioning of the metatarsophalangeal subluxation or dislocation of the lesser rays, thereby preserving the metatarsophalangeal joints, thus leaving the function of the aponeurosis plantaris intact. As a result of this it can be expected that unrolling of the forefoot is unaffected and therefore a better function of the forefoot remains.

Aim: To assess the results of forefoot reconstruction using the repositioning technique performed in 54 feet (39 patients) by one surgeon using this technique.

Methods: Fifty-four feet (39 RA patients) were treated with the technique of repositioning the metatarsophalangeal subluxation or dislocation. All surgery was performed by one orthopaedic surgeon. In case of severe deformity of the metatarsophalangeal joint of the hallux, an arthrodesis was performed. All patients were reviewed after a mean follow up of 40 months (range 12–72 months) and an AOFAS [American Orthopaedic Foot and Ankle Society] foot score, and FFI [Foot Function Index] were obtained.

Results: At a mean of 40 months (SD=15.6 months) postoperatively, the mean AOFAS forefoot score was 69.80 (SD=11.8) if, in addition of repositioning the metatarsophalangeal joints, an arthrodesis of the hallux was performed. In patients with no operation on the hallux, the AOFAS score was 42.2 (SD=18.8) (P=0,001). The postoperative FFI-scores were 74.0 (SD=17.5) and 57.6 (SD=14.6) respectively (P=0,026)

Conclusions: Reconstruction of the rheumatoid forefoot by repositioning the metatarsophalangeal joints of the lesser rays, thereby preserving the joints, can be considered a procedure that provides improvement in the clinical outcome. Best results were seen in patients in whom, in addition of reconstruction of the lesser rays, an arthrodesis of the hallux was performed.