Influence of preoperative factors on the gain in flexion after total knee arthroplasty.

UNLABELLED: Final flexion mobility after a total knee arthroplasty is an important factor in patient comfort. Some patients gain in flexion mobility, others do not. Is it possible to identify the clinical factors related to the patient that predicted the final gain in flexion? MATERIALS AND METHODS: A multicenter retrospective study directed by the Société française de la hanche et du genou (SFHG) was conducted on 1601 cases of total knee arthroplasty that had presented no complications and a minimal follow-up of 2 years. The gain in flexion was assessed by the difference between the preoperative and the final range of flexion. The range of the gain in flexion was tested based on eight factors: age, gender, etiology, body mass index, frontal deformity, preoperative flexum deformity and four levels of preoperative mobility: < 90°, 90°-109°, 110°-129°, and ≥ 130°. RESULTS: A mean gain in flexion of 8.4°±14° was found for the overall series. In 66% of cases, we found an increase of flexion and in 19% a loss of flexion. In cases with BMI higher than 35, varus deformity with an HKA angle<166°, or flessum greater than 5°, the gain in flexion was significantly higher. A significantly different gain in flexion (P<0.0001) was found in the four levels of preoperative flexion: the greatest gain in flexion was found in the "<90°" group, then this gain was less in the next two groups, to become a significant decrease in the "≥130°" group. A decrease in flexion was noted in 51% of the cases in the latter group. Other factors such as age, sex, and etiology had no influence on the gain in flexion. DISCUSSION: After TKA, a gain in flexion was often noted. The amount of gain depended on the preoperative range of flexion: the lower this level was, the more flexion increased. The presence of a varus deformity, morbid obesity, or flessum was associated with greater gain in flexion, even if the final flexion was lower than the mean flexion in the overall population. The search for these factors made it possible to predict a gain in flexion and discuss this with the patient. LEVEL OF EVIDENCE: Level IV. Multicenter retrospective study.

Should we resurface the patella in total knee replacement? Experience with the Nex Gen prothesis.

Patellar resurfacing is a controversial issue in primary total knee replacement. So, we took advantage of a large study to try and answer this question. An open prospective multicentric study was conducted about the outcome of the Nex Gen Total Knee prosthesis with clinical and radiological follow-up at regular intervals (1, 2 and 5 years). The data were centrally collected and analyzed by independent observers. A total of whole 5,915 cases were included (487 in the French group); incidences of patello-femoral pain were observed in both French and international groups and compared between cases with or without resurfaced patellae. Only osteoarthritic cases were selected for this particular study. Statistical analysis was performed using a Pearson's Chi-square test with a 95% confidence interval. The frequency of preoperative pain was significantly higher in the French group; 85.1% versus 66.6% (p<0.05). No patello-femoral pain appeared in preoperatively painless patients in the French group. The frequency of lateral patellar release was similar in both groups. 35.7% of the patellae were resurfaced in the international group versus 98.8% in the French one. At 2 years, patello-femoral pain was observed in 6.3% of cases in the former group versus 0.7% in the latter one. The risk of having patello-femoral pain was 9.45 times higher in the international group. When considering resurfaced cases in both groups the risk of having anterior knee pain was not significantly different (p=0.35). In the French group, one case out of nine (11.1%) with patello-femoral pain had not been resurfaced, while 129 cases out of 151 (85.4%) had not had a resurfacing in the international group. This emphasizes the effect of patellar implant on pain. Although patello-femoral pain is multifactorial, this analysis tool is powerful in getting rid of the "center effect " (cf Swedish register). Even if a longer follow-up for confirmation is needed, our data favor patellar resurfacing with this type of implant in spite of the fact that the trochlear design was considered as anatomical.

[Patellar reconstruction during total knee arthroplasty after previous patellectomy]. / Reconstruction patellaire au cours d'une arthroplastie totale sur genou patellectomisé

PURPOSE OF THE STUDY: In order to limit the consequences of prior total patellectomy on knee function after total knee arthroplasty, we propose an original technique using an en bloc patellar graft to reconstruct the quadriceps lever arm. The purpose of this work was to describe the technique and present preliminary results obtained in seven patients. PATIENTS AND METHODS: Seven en bloc patellar grafts were performed in seven patients (6 women and 1 man) during total knee arthroplasty procedures for femorotibial degenerative joint disease after prior patellectectomy (mean 13 years before arthroplasty, range 5-20 years). We implanted three posterior stabilized prostheses, one ultracongruent prosthesis, two prostheses preserving the posterior cruciate ligament, and one bi-cruciate prosthesis. The patella was reconstructed with an autologous bone graft fashioned from the tibial plateau in six cases, and with a homologous graft fashioned from a bone-bank femoral head in one. Transosseous sutures were used to fix the graft to the extensor system. A polyethylene button was cemented on five of the grafts. RESULTS: Active extension was defective in five knees prior to the patellar graft and in only one knee after patellar reconstruction. The IKS knee score improved from 41 points (range 35-45) before surgery to 78 points (range 55-95) after grafting and the IKS function score from 35 (range 5-50) to 72 (range 40-100). Four of the seven grafts were removed (eight weeks to five years after implantation, mean two years) mainly due to failure of fixation leading to progressive migration. Follow-up varied from eight weeks to six years. Mean follow-up for the three grafts still in place was 4.6 years (4-6 years). After removing the patellar graft (4 knees) the IKS knee score decreased to 68 points (20-95) and the IKS function score to 62 points (30-100). Lack of active extension reappeared in three of the knees after removing the patellar graft but was not observed in the three knees with the patellar graft in place (and flexion was at least 110 degrees ). Microradiography of the patellar graft explanted after two years revealed peripheral corticalization with areas of living bone tissue seen on the pathology specimens. Inversely, the autografts explanted at eight weeks and at five years exhibited bone necrosis. CONCLUSION: This preliminary study shows that patellar autograft can improve the performance of total knee arthroplasty on patellectomized knees. The fixation technique must be improved using transosseous transverse sutures in addition to peripheral sutures in order to limit secondary migration of the graft. A patellar autograft fixed into the extensor system can remain viable two years after implantation. This technique can be proposed when total knee arthroplasty is indicated for a patellectomized knee, particularly in patients with lack of active extension.

[Articular fractures of the base of the first metacarpal. Comparative study of direct osteosynthesis and closed pinning]. / Les fractures articulaires de la base du premier métacarpien. Etude comparative de l'ostéosynthèse directe et de l'embrochage extra-focal.

The authors retrospectively studied 35 articular fractures of the base of the first metacarpal, with an average follow-up of 3 years. Treatment consisted of closed reduction and pinning in 19 cases, open reduction and rigid fixation in 16 cases. Results were estimated in terms of pain, range of movement (flexion-adduction arc and abduction-extension arc), strength and X-rays. There was no significant difference between the two groups, for age, sex, occupation, side and postoperative care. Only one significant difference between both procedures was found: flexion-adduction was better after osteosynthesis than after closed pinning (p = 0.03). The authors observed a better range of flexion-adduction and pinch strength after treatment of Bennett's fracture. Radiographic features were not different at follow-up between open and closed osteosynthesis.

[Contribution of x-ray computed tomography to the diagnosis and treatment of fractures of the acetabulum. Apropos of 88 cases]. / Apport de la tomodensitométrie au diagnostic et au traitement des fractures du cotyle. A propos de 88 cas.

Eighty-eight recent fractures of the acetabulum have been investigated by standard antero-posterior and oblique radiographs and by CT scanning. The results of the two examinations have been compared. Whilst the type of fracture is well defined by radiography, CT scanning frequently reveals associated lesions, not seen on standard radiographs, which may have an effect on the relationship between the femoral head and the acetabulum. Thus, out of 28 cases with intra-articular fragments, 18 were not visible on standard radiographs and were discovered by CT scan. Similarly, out of 25 peripheral impactions of the acetabulum, 16 were not visible on standard radiographs, of 12 notching lesions of the femoral head, nine were not visible and six out of 23 sacro-iliac displacements were not recognised. CT scanning improved the appreciation of congruence between the femoral head and the acetabular roof in 15 cases and between the femoral head and the acetabulum in 24 cases. Only in 17 patients was there complete agreement between standard radiographs and CT scans. In particular, there is no doubt about the value of CT scanning in comminuted fractures and in fractures of the posterior wall or posterior column. It is a useful adjunct in the choice between conservative and operative treatment.

[X-ray computed tomography in fractures of the acetabulum]. / Apport de la tomodensitométrie dans les fractures du cotyle.

Radiographic assessment of these fractures remains difficult. Conventional techniques according to Letournel show the lesions but not to the best advantage, for instance the "congruency" of femoral head with acetabulum. 54 CT scan were performed (1982-1984) every time a doubt was persisting. Incarcerations of fragments, impactions of the acetabulum, sacro-iliac joint disjunctions, congruency and lesions of femoral head are much better seen with scanner. In planing the surgical therapy (or orthopedic), CT scan add a great deal to the information and dramatically improves the results.

[Functional results of tibio-tarsal arthrodeses. Apropos of 52 reviewed cases]. / Résultats fonctionnels de l'arthrodèse tibio-tarsienne. A propos de 52 cas revus.

Fifty-two patients with ankle arthrodesis were reviewed after an average follow-up of 7 years with a range between 2 and 22 years. Two-thirds of the patients had good results and 1 in 4 had fair results. In 4 cases there were bad results. Thirty-seven patients could walk without any limitation thanks to mobility of the mid-tarsal joint. Most of the patients developed radiological arthrosis of the subtalar joint with limited movement in 29 instances. In contrast, hypermobility of the mid-tarsal joint was present in almost half of the cases. Good functional results were related to the preservation of mobility in the subtalar and mid-tarsal joints. The time required to obtain a good functional result was about one-and-a-half years. After this the results were stable, provided that the ankle fusion was in a good position. Most of the poor results were related to arthrosis of the sub-talar joint or trophic changes. Secondary extension of fusion to other joints was deceptive. It is concluded that combined arthrodesis of the tibio-talar and sub-talar joints should be done only in cases of severe arthrosis. In other cases, the mobility of the sub-talar and mid-tarsal joints should be preserved.

[Acetabular fractures and sacroiliac dislocations]. / Fractures du cotyle et disjonctions sacro-iliaques.

Involvement of the sacro-iliac joint is frequently associated with acetabular fractures. It was noted on 23 occasions in fractures of both columns of the acetabulum. Tomodensitometry is a key examination which shows lesions which could be missed on standard X-Rays. Dislocations of the sacro-iliac joint diminished the possibility of exact reduction. In 23 cases, only three sacro-iliac lesions were anatomically reduced and 13 hips were well centered. The results obtained after surgical treatment were better than after conservative treatment. This explained the finding that 10 hips developed arthrosis in 14 patients treated conservatively and only 3 in 9 treated surgically. The sacro-iliac involvement was either an anterior opening of the joint leading to an antero-posterior excentration of the hip, or an inferior opening leading to a lateral shift of the iliac bone and a vertical orientation of the acetabulum. In several cases, both types of displacement were present. The diagnosis of the sacro-iliac joint lesion is helped by tomodensitometry though it can also be made by good antero-posterior pelvic radiographs. Conservative treatment using traction was unable to reduce the sacro-iliac lesion, and in some cases it increased the displacement of the iliac bone. Treatment should be by reduction, either using external fixators or by internal fixation.