M. von Knoch

Trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia: A 4- TO 14-YEAR FOLLOW-UP STUDY

We investigated the clinical and radiological outcome of trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia in 38 consecutive patients (45 knees) with a mean follow-up of 8.3 years (4 to 14). None had recurrence of dislocation after trochleaplasty. Post-operatively, patellofemoral pain, present pre-operatively in only 35 knees, became worse in 15 (33.4%), remained unchanged in four (8.8%) and improved in 22 (49%). Four knees which had no pain pre-operatively (8.8%) continued to have no pain. A total of 33 knees were available for radiological assessment. Post-operatively, all but two knees (93.9%) had correction of trochlear dysplasia radiologically but degenerative changes of the patellofemoral joint developed in 30% (10) of the knees. We conclude that recurrent patellar dislocation associated with trochlear dysplasia can be treated successfully by trochleaplasty, but the impact on patellofemoral pain and the development of patellofemoral osteoarthritis is less predictable. Overall, subjective patient satisfaction with restored patellofemoral stability after trochleaplasty appeared to outweigh its possible sequelae.

The accuracy of free-hand cup positioning - a CT based measurement of cup placement in 105 total hip arthroplasties

We studied 105 patients who received a total hip arthroplasty between June 1985 and August 2001 using freehand positioning of the acetabular cup. Using pelvic CT scan and the hip-plan module of SurgiGATE-System (Medivision, Oberdorf, Switzerland), we measured the angles of inclination and anteversion of the cup. Mean inclination angle was 45.8°±10.1° (range: 23.0–71.5°) and mean anteversion angle was 27.3°±15.0° (range: −23.5° to 59.0°). We compared the results to the “safe” position as defined by Lewinnek et al. and found that only 27/105 cups were implanted within the limits of the safe position. We conclude that a safe position as defined by Lewinnek et al. [13] was only achieved in a minority of the cups that were implanted freehand.RésuméNous avons étudié 105 malades qui ont eu une Arthroplastie Totale de la Hanche entre juin 1985 et août 2001 avec positionnement manuel de la cupule acétabulaire. Utilisant une tomodensitométrie pelvienne et le module de hanche de SurgiGATE© - System (Medivision, Oberdorf, Suisse) nous avons mesuré les angles d’inclination et d’antéversion de la cupule. L’angle moyen d’inclination était 45.8°±10.1° (gamme: 23.0° à 71.5°) et l’angle moyen d’antéversion était 27.3°±15.0° (gamme: -23.5° à 59.0°). Nous avons comparé les résultats à l’orientation de sécurité définie par Lewinnek et al. et nous avons trouvé que seulement 27/105 cupules ont été implantées dans les limites de l’orientation correctes. Nous concluons qu’une orientation de sécurité, comme défini par Lewinnek et al. [13] n’a été obtenue que dans une minorité des cupules implantées manuellement.

Fracture of the lateral process of the talus in snowboarders

We investigated the clinical and radiological outcome after unilateral fracture of the lateral process of the talus in 23 snowboarders with a mean follow-up of 3.5 years (12 to 76 months). In this consecutive cohort study both operative and non-operative cases were considered. The mean American Orthopaedic Foot and Ankle Society hindfoot score was 94 (82 to 100). The non-operative group of seven with a minimally-displaced fracture scored higher (98 points) than the operative group of 16 with displaced or unstable fractures (93 points). In 88% of operative cases, significant concomitant hindfoot injuries were found at operation. All but eight (35%) patients (six operative and two non-operative) regained their pre-injury level of sporting activity. Subtalar osteoarthritis was present in nine (45%) of the 20 patients available for radiological review, including one late-diagnosed non-operative case and eight operative cases with associated injuries or fracture comminution. The outcome after fracture of the lateral process of the talus in snowboarders is favourable provided an early diagnosis is made and adequate treatment, which is related to the degree of displacement and associated injuries, is undertaken.

Unsuccessful surgical treatment of hip dislocation in congenital sensory neuropathy with anhidrosis: A CASE REPORT

A six-year-old girl with congenital sensory neuropathy with anhidrosis (CSNA) presented with bilateral hip dysplasia and subluxation on the right side. Conservative treatment of the hips by closed reduction and a plaster cast was unsuccessful. When aged seven years the patient had an intertrochanteric varus rotation osteotomy on the right side, but subluxation was again evident after five months. A Salter-type pelvic osteotomy was carried out followed by immobilisation, but one year later subluxation was present in the right hip and dislocation in the left. At the age of nine years, the right femoral head resembled a Charcot joint, although walking ability was preserved. In patients with CSNA, surgery may not always be advisable.