[Mid-term results of Wallaby I posterior cruciate retaining total knee arthroplasty: a prospective study of the first 425 cases]

PURPOSE OF THE STUDY

Posterior Wallaby I is a fixed polyethylene tibial plateau prosthesis enabling preservation of the posterior cruciate ligament (PCL). Its asymmetrical and divergent femoral condyles articulate with also asymmetrical tibial plateaus. The purpose of this prospective study was to analyze outcome of the first 425 Wallaby I prosthesis of the Guepar group implanted for first-intention treatment.

MATERIALS AND METHODS

These 425 prostheses were implanted from December 1992 to February 1995 by senior and junior surgeons. Mean patient age at implantation was 70.5 years. 91% had primary or secondary osteoarthritis and only 8.9% had inflammatory rheumatoid disease. The mean preoperative IKS score was 25.34 points and the IKS function score was 29.04. 10.35% of knees were aligned normally (mechanical axis between 2 degrees varus and 3 degrees valgus) according to the IKS criteria (Ewald), 24% presented valgus > or = 4 degrees and 65.6% varus > or = 3 degrees. All tibial and patellar components (except one) were cemented, 5.8% of the femoral pieces were inserted without cement. All but 11 patellae were resurfaced. Clinical outcome was assessed with the IKS score and radiological outcome with the IKS criteria. The patella was considered to be tilted when the alpha angle was > 5 degrees and dislocated when the AA' distance was > 5 mm. The chi-square test was used for comparison of quantitative variables (significance set at 0.05).

RESULTS

Early postoperative complications were rare: two infections cured with debridement-lavage and antibiotics without removal of the prosthesis, one peronal nerve palsy which regressed partially, ten late unions without clinical consequence (particularly in the inflammatory rheumatoid patients). Twenty-six prostheses were followed less than one year (eight patients died and eighteen were lost to follow-up) and 84 less than five years (27 patients died and 57 lost to follow-up before five years). 315 prostheses were followed for more than five years (5-9 years) with a mean follow-up of 6.3 years. Among the 399 prostheses followed for one year or more, we noted: four infections including three requiring change of the prosthesis (one cured by arthroscopic lavage), two aseptic loosenings which were revised (one global one tibial), one tibial loosening and three patellar loosenings which were not revised, and two femoral ossifications limiting joint motion but improved by arthrolysis and resection of the ossifications. Three patients experienced anterior pain requiring secondary patellar resurfacing in two and section of the lateral patellar wing in one. Ninteen patellar fractures (4.7%) were noted, including 17 with no significant functional impact which were not revised. The mean IKS knee score among prostheses followed for five years was 90.5 points, with mean motion 110.5 degrees. Mean IKS function score was 61.63 points. 72.9% of the knees were aligned, 22.2% in varus and 4.9% in valgus. The mechanical axis of 94.3% of the knees was between 5 degrees varus and 5 degrees valgus. Prosthesis survival at eight years (Kaplan-Meier method) was 97.7% considering all reasons for prosthesis removal and 98.5% for removal for aseptic loosening.

CONCLUSION

This prospective multicentric study demonstrated that the results obtained with the Wallaby I prosthesis are as good as those obtained with other prostheses sparing the PCL and published in the literature. Preservation of the PCL enables better knee stability, correct motion (110.5 degrees in our series) with almost no radiological wear of the tibial polyethylene at eight years. The only worrisome complication is patellar fracture.

Hybrid alumina total hip arthroplasty using a press-fit metal-backed socket in patients younger than 55 years. A six- to 11-year evaluation

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.

[Arthroscopic release for knee joint stiffness after total knee arthroplasty]

PURPOSE OF THE STUDY

Overall, the results of total knee replacement surgery are quite excellent, both with regard to pain and range of motion. Pain relief is obtained in more than 95% of the cases and more than 90% of the patients are able to bend their knee over 90 degrees. Nevertheless, in a small number of cases, stiffness can be an impairment.

MATERIAL AND METHODS

Between 1992 and 1998, six arthroscopic releases were performed on six patients who had undergone total knee replacement. The six patients suffered from unacceptable stiffness. The average age of the patients was 68.5 years, and the time elapsed from implantation to arthroscopy averaged 24 months (6 months to 6 years). Average follow-up was 19 months (6 to 96 months). The six stiff knees were treated with arthroscopic debridement of fibrous tissue around the patella and quadriceps tendon (to improve extension) and by arthroscopic division of the medial and lateral retinacula (to address flexion). A gentle manipulation was carried out following lysis of adhesions, using a slight pressure on the tubercle to avoid fractures and disruptions of the extensor mechanisms. Postoperatively, immediate physical therapy was performed including continuous passive motion and active muscular contraction. Early weight bearing was allowed.

RESULTS

The average flexion contracture decreased from 9 degrees prior to arthroscopy to 2.5 degrees at last follow-up. Average flexion increased from 70 to 100 degrees. Maximal improvement was obtained at three months.

DISCUSSION

Results were found to be quite good, with a final knee score of 93 and a function score of 92 (following International Knee Society scoring).

CONCLUSION

Arthroscopic release following total knee replacement complicated by joint stiffness provides a satisfactory increase in range of motion.

Hydroxyapatite-coated versus grit-blasted femoral stems. a prospective, randomised study using EBRA-FCA

We have carried out a prospective, randomised study designed to compare the long-term stability of the stem of cementless femoral implants with differing surface configurations. A total of 50 hips (46 patients) was randomised into two groups, according to whether the medullary stem had been grit blasted (GB) or coated with hydroxyapatite (HA). Both femoral prostheses were of the same geometrical design. We used Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) to assess the stability of the stem. The mean follow-up was for 8.66 years. The mean migration of the stem was 1.26 mm in the HA group compared with 2.57 mm in the GB group (Mann-Whitney U test, p = 0.04). A mixed model ANOVA showed that the development of subsidence was statistically different in the two groups during the first 24 months. After this subsidence increased in both groups with no difference between them. Our results indicate that, with the same design of stem, HA coating enhanced the stability of the femoral stem when compared with GB stems.

Hydroxyapatite-coated versus grit-blasted femoral stems

We have carried out a prospective, randomised study designed to compare the long-term stability of the stem of cementless femoral implants with differing surface configurations. A total of 50 hips (46 patients) was randomised into two groups, according to whether the medullary stem had been grit blasted (GB) or coated with hydroxyapatite (HA). Both femoral prostheses were of the same geometrical design. We used Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) to assess the stability of the stem. The mean follow-up was for 8.66 years.

The mean migration of the stem was 1.26 mm in the HA group compared with 2.57 mm in the GB group (Mann-Whitney U test, p = 0.04). A mixed model ANOVA showed that the development of subsidence was statistically different in the two groups during the first 24 months. After this subsidence increased in both groups with no difference between them. Our results indicate that, with the same design of stem, HA coating enhanced the stability of the femoral stem when compared with GB stems.

Press-fit metal-backed alumina sockets: a minimum 5-year followup study

Two hundred thirty-four consecutive alumina-on-alumina hip replacements using a press-fit metal-backed socket, performed on 214 patients (98 women, 116 men) have been reviewed. These included 201 primary procedures and 33 revision procedures. The median age of the patients at the time of surgery was 62 years (range, 21-83 years). Fourteen patients (16 hips) died from unrelated causes. Eleven patients (11 hips) underwent a total hip arthroplasty revision for recurrent dislocation (one hip), deep infection (two hips), fracture of alumina femoral head (one hip), persistent hip pain (one hip) and aseptic loosening (six hips). The survival rate after 9 years was 93.4% when revision of the prosthesis was considered the end point, and 97.4% if revision of the prosthesis for aseptic loosening was considered the end point. Results were assessed in the surviving patients with a minimal 5-year followup (170 patients, 184 hips). At the median followup of 7.8 years, the average Merle d'Aubigné and Postel score had improved from 11.9- to 17.7. Results were graded as excellent in 148 hips (80.5%), very good in 31 hips (17%), good in two hips (1%), and fair in three hips (1.5%). Radiologic data were documented for 134 patients (143 hips). Three sockets (2%) had a complete and nonprogressive radiolucent line less than 1-mm thick, one stem (0.7%) had lucencies involving five zones, and two stems (1.4%) had isolated femoral osteolysis. Neither component migration nor acetabular osteolysis were detected. A press-fit metal-backed socket may offer a good solution for alumina socket fixation when combined with a careful surgical technique of implantation.

Total knee replacement after failed tibial osteotomy: results of a matched-pair study

Sixty-three total knee replacements were performed after a failed tibial osteotomy. The goal of this study was to compare the perioperative problems and the outcome of this group of patients (study group) to a group of patients with primary arthroplasties matched for age, gender, length of follow-up, weight, and preoperative Charnley class. Operative problems were more frequently encountered in the study group, with 7 tibial tubercle elevations and 15 lateral retinaculum releases needed, whereas lateral retinaculum release was necessary for only 1 knee in the control group. Outcome was assessed using both the International Knee Society (IKS) scoring system and Hospital for Special Surgery (HSS) knee score. The follow-up period averaged 4.6 years. The IKS score of the control group was significantly higher, averaging 80.9 +/- 13.8, whereas it was 74.4 +/- 14.8 for the study group (P = .0001). Among the parameters included in the knee score, only pain was significantly different with the control group (P = .03). The IKS function score and the HSS score were not statistically different. Conversion of a failed tibial osteotomy is a technically demanding procedure. Careful preoperative planning is needed. Results, especially on pain, appeared to be inferior to those for primary arthroplasties.

Femoral head osteonecrosis after bone marrow transplantation

Thirty-five patients with bilateral osteonecrosis of the femoral head after bone marrow transplantation were reviewed retrospectively. The median age at the time of transplantation was 26 years. The first symptoms occurred within 2 years of transplantation. At presentation, 18 of the patients reported pain in both hips, 17 had symmetric radiographic lesions, and 39 of the hips had collapsed. Medical treatment was indicated initially. At the final examination before surgery (median, 3.5 years), 31 patients had bilateral hip pain, 22 patients had symmetric radiographic lesions, and 56 of the hips had collapsed. Fifty-seven of the hips required surgery, including one open drainage, four core decompressions, six cup arthroplasties, and 46 primary total hip replacements. Six hips (four core decompressions; two cups) later underwent total hip replacement revision, and a deep infection developed in one. By considering the requirement of a total hip replacement as a failure of conservative treatment, the rate of survival of the femoral head was 30% 5 years after the transplant. There was no significant difference between the Ficat grades, except for Grade 0, which showed a higher survival rate. The study of the specific features of the osteonecrosis may lead to the recommendation of primary total hip arthroplasty after failure of the medical treatment.

[Bilateral total hip prosthesis in osteopetrosis. Apropos of a case. Review of the literature]

PURPOSE OF THE STUDY

The authors report an original case of Albers-Schönberg's disease and describe its surgical treatment.

MATERIAL

Comparison between roentgenogram of the pelvis at the age of 9 and 46 years showed the original evolution of coxa vara in a case of osteopetrosis. A 46 year old male had severe pain and instability in both hips related to numerous problems consisting of: 1) on the right side: subtrochanteric femoral non-union after repeated fractures, head and neck femoral disappearance associated to dislocation. 2) on the left side: acetabular dysplasia, osteoarthritis and subtrochanteric femoral fracture that had fusionned. Total hip arthroplasty was performed on both hips.

RESULT

Clinical result was good in both hips (PMA score = 6-6-4) at the latest follow-up (four years on the left side and three years and four months on the right side). The surgical procedures were difficult because of the hardness and brittle character of the bony substance and because of non unions and deformities. Special care was required to avoid shattering femoral diaphysis and false routes during creation of a new medullary canal.

CONCLUSION

Total hip prosthesis represents a functionnal salvage procedure in patients with Albers-Schönberg's disease.

[Benign osteoblastoma of the hand. A case--review of the literature]

One case of a benign osteoblastoma, localised on the proximal phalanx of right thumb is reported. Three points are emphasized: the low frequency in the hand, only six observations are reported in the English literature, one from Jaffe (1932) and four from Lichtenstein (1964) and one from Mosher and coll (1978). The non-specificity of the signs and X-ray are must consider chondroma, giant cell tumor, chondrosarcoma or aneurysmal cyst. The lesion is benign and so the treatment must be conservative.

Ulnar neuritis in Hansen's disease results of fifty neurolyses in the arm and elbow

Fifty cases of ulnar nerve neuritis in Hansen disease are reported. The authors analyse the type of lesion, the clinical feature, the treatment, and the results of neurolysis. Many points are emphasized: the requirement to an association antileprosy, chemotherapy and corticotherapy with a careful neurolysis; pain and paresthesia were relieved immediately after neurolysis, recovery within two years after neurolysis; the amount of recovery was directly related to the extent and stage of involvement of the nerve; and thus the sooner procedure give the best result.

CERAMIC-CERAMIC AND METAL-POLYETHYLENE TOTAL HIP REPLACEMENTS

We made a semiquantitative study of the comparative histology of pseudomembranes from 12 loose cemented ceramic-ceramic and 18 metal-polyethylene total hip replacements. We found no significant difference in cellular reaction between the two groups, but there was a major difference in the origin of the particulate debris. In the metal-polyethylene group, polyethylene of articular origin was predominant, while in the ceramic-ceramic group the cellular reaction appeared to be a response to zirconia ceramic particles used to opacify cement used for fixation.

Isolation and characterisation of the debris showed that the zirconia particles formed the greatest proportion (76%) in ceramic-ceramic hips, while alumina debris of articular origin formed only 12%.

Our study has indicated that aseptic loosening of ceramic cups is not due to a response to debris generated at the articular interface, but to mechanical factors which lead to fragmentation of the cement.

Ceramic-ceramic and metal-polyethylene total hip replacements: comparison of pseudomembranes after loosening

We made a semiquantitative study of the comparative histology of pseudomembranes from 12 loose cemented ceramic-ceramic and 18 metal-polyethylene total hip replacements. We found no significant difference in cellular reaction between the two groups, but there was a major difference in the origin of the particulate debris. In the metal-polyethylene group, polyethylene of articular origin was predominant, while in the ceramic-ceramic group the cellular reaction appeared to be a response to zirconia ceramic particles used to opacify cement used for fixation. Isolation and characterisation of the debris showed that the zirconia particles formed the greatest proportion (76%) in ceramic-ceramic hips, while alumina debris of articular origin formed only 12%. Our study has indicated that aseptic loosening of ceramic cups is not due to a response to debris generated at the articular interface, but to mechanical factors which lead to fragmentation of the cement.

AVASCULAR NECROSIS OF THE FEMORAL HEAD AFTER ALLOGENIC BONE-MARROW TRANSPLANTATION

After an allogenic bone-marrow transplant, a vascular necrosis of the femoral head may affect young adults, producing destructive lesions which require hip replacement. We have reviewed 27 consecutive such total hip arthroplasties (THA) at a minimal follow-up of two years. Of these, 20 were primary operations for Ficat (1985) stage-III and stage-IV lesions, and seven were revisions after the failure of previous surgery. The median age at operation was 30 years (17.5 to 44). The prostheses had a cemented, collared titanium-alloy stem, an alumina-alumina joint, and a press-fit socket. Seven had a titanium-alloy metal back and 20 had all-alumina cups of which six had to be cemented.

At an average follow-up of five years, no patient had been lost to follow-up. One had died from septicaemia after two years and another with chronic graft-versus-host disease developed a deep infection 2.5 years postoperatively and had a successful revision. There were no revisions for aseptic loosening. The clinical results on the Merle d’Aubigné and Postel (1954) scale were very good or excellent in 23 hips (88%), good in one and fair in two. Ten hips showed incomplete acetabular radiolucencies less than 1 mm thick, but there were no radiolucent lines around the stems.

We conclude that for these difficult patients THA with ceramic joints and careful technique provides the best short- and medium-term option after the failure of medical treatment.

Avascular necrosis of the femoral head after allogenic bone-marrow transplantation. A retrospective study of 27 consecutive THAs with a minimal two-year follow-up

After an allogenic bone-marrow transplant, avascular necrosis of the femoral head may affect young adults, producing destructive lesions which require hip replacement. We have reviewed 27 consecutive such total hip arthroplasties (THA) at a minimal follow-up of two years. Of these, 20 were primary operations for Ficat (1985) stage-III and stage-IV lesions, and seven were revisions after the failure of previous surgery. The median age at operation was 30 years (17.5 to 44). The prostheses had a cemented, collared titanium-alloy stem, an alumina-alumina joint, and a press-fit socket. Seven had a titanium-alloy metal back and 20 had all-alumina cups of which six had to be cemented. At an average follow-up of five years, no patient had been lost to follow-up. One had died from septicaemia after two years and another with chronic graft-versus-host disease developed a deep infection 2.5 years postoperatively and had a successful revision. There were no revisions for aseptic loosening. The clinical results on the Merle d'Aubigné++ and Postel (1954) scale were very good or excellent in 23 hips (88%), good in one and fair in two. Ten hips showed incomplete acetabular radiolucencies less than 1 mm thick, but there were no radiolucent lines around the stems. We conclude that for these difficult patients THA with ceramic joints and careful technique provides the best short- and medium-term option after the failure of medical treatment.

Tibial tunnel enlargement after anterior cruciate ligament reconstruction by autogenous bone-patellar tendon-bone graft

This retrospective study was designed to evaluate changes in the diameter of the tibial tunnel over time following the reconstruction of the anterior cruciate ligament (ACL) with a bone-patellar tendon-bone autograft in 44 patients. The changes in the geometry of the bone tunnels were measured radiographically during the immediate postoperative period and at time intervals between 3 and 36 months after surgery. The dimensions at 1 year were correlated with the 1-year clinical results. The distance between the sclerotic margins of the tibial tunnel was measured at the distal tunnel exit on the medial tibial cortex, in the middle of the tunnel, and proximally at the level of the joint line. The dimensions were calculated by using a magnification factor determined by reference to the interference screw of known diameter located within the tunnel. The position of the centre of the tibial tunnel with regard to Blumensaat's line was also measured. The average tunnel diameter at the proximal tibial exit increased from 12 +/- 1.9 mm (mean +/- standard deviation) postoperatively to 14 +/- 2.2 mm at 3 months. The average proximal tunnel diameter did not significantly change from 3 months to 2 years, and then decreased to 13 +/- 2.4 mm at 3 years. At 1 year, most of the patterns of osteolysis were of the cone type (57%), followed by the cavity type (40%) and line type (3%). The degree of osteolysis was not related to the tibial tunnel position with respect to Blumensaat's line. There was no correlation between the changes in tunnel diameter and either the IKDC score or the residual joint laxity measured by a KT-100 arthrometer. The aetiology of tunnel enlargement is currently unknown. Possible factors responsible for bone resorption include micromotion of the graft relative to the tunnel wall, leading to an inflammatory response in the tunnel, or stress shielding of the tunnel wall proximal to the interference screw.

[Radiologic and MRI evaluation of intra-articular ligamentoplasty using a patellar tendon. Correlations with anatomical results]

INTRODUCTION

the purpose of this study was to evaluate the influence of the graft positioning on the clinical outcome and MRI signal of the graft as well, following ACL reconstruction using the central one-third of the patellar tendon.

MATERIAL AND METHODS

twenty one patients having a chronic anterior instability sustained a modified Marshall-Mac Intosh procedure, while 15 having a subacute torn ACL had an ACL reconstruction using a free bone-patellar tendon-bone graft. The patients were retrospectively reviewed with a 1.8 year average follow-up (1-3 years). The clinical result was evaluated through the comparative range of motion, the residual laxity as measured with the KT 1000 arthrometer, and the pivot shift test. The roentgenographic analysis was performed from AP and ML views, made first on one-leg standing with the knee at 30 degrees of flexion, and then in "zero" extension with active quadriceps contraction. Lines were drawn to visualise the location of the tibial and femoral tunnels in relation to the tibial plateaus and the roof of the intercondylar notch represented by the Blumensaat line. The analysis of the AP IRM views of the graft allowed to discriminate between homogeneous and heterogeneous graft signals.

RESULTS

on lateral roentgenograms of normal knees it was found that the Blumensaat line crossed the surface of the medial tibial plateau at its anterior third, at 30 +/- 9 per cent (20-40 per cent range), demonstrating the variability of the intercondylar roof inclination. The range of motion was normal in 22 patients (group 1), 8 patients had a flexion deficit (group II), and 6 exhibited an extension deficit (group III). The residual laxity was similar in each group (p > 0.05). When comparing group III to group I, patients from group III had a tibial tunnel significantly more anterior with regard to the Blumensaat line (p < 0.02). In group III, all patients exhibited an heterogeneous MRI graft signal (p < 0.05), and the angle between the intraarticular part of the graft and the tibial tunnel was higher (p < 0.001). These findings were not observed in group II where the location only of the femoral tunnel seemed to influence the flexion deficit (p > 0.05).

DISCUSSION AND CONCLUSION

this study demonstrated that the location of the tibial tunnel with regard to the roof of the intercondylar notch, when the knee is in "zero" extension, was the most relevant parameter controlling the extension deficit resulting from a graft impingement. No relation was found between the tibial tunnel location with regard to the tibial plateaus and the mobility deficit. Graft impingement also was always associated with an heterogenous graft MRI signal.

CLINICAL RELEVANCE

when reconstructing the ACL care must be taken when inserting the K-wire aimed to guide the tibial drill, to obtain a proper position with regard to the roof of the intercondylar notch. The K-wire location must be checked in "zero" extension. Intra-operative X-rays may help.

Alumina-alumina hip replacement in patients younger than 50 years old

From April 1977 to December 1990, 131 total hip arthroplasties were performed on 113 patients younger than 50 years of age (median, 41 years); 64 were men and 49 women. The majority were active people. Sixty-six hips had no previous operations, and 33 had at least one previous arthroplasty. The femoral component was a cemented collared titanium alloy stem, and alumina socket was cemented for 99 hips and press-fit for 32. The mean follow-up period was five years, with 32 hips followed for more than ten years. Revision arthroplasty was considered as a failure. Survivorship analysis depicted a 97.5% rate of survival at five years, an 89.4% rate at ten years, and an 86.2% at 11 years. Nine revisions were performed: one experienced a femoral head rupture after three years, one had bipolar loosening, one experienced femoral cystic formation, and six were revised for acetabular cup loosening, all from the cemented group. Two revisions occurred on the same patient. No stem revision was necessary before ten years. Only one of these revisions was required in patients aged 40 or younger (64 patients). Alumina-alumina friction is an extremely interesting phenomenon in young patients, and could be related to the low wear debris production.

Roentgenographic and magnetic resonance imaging of anterior cruciate reconstruction using a patellar tendon graft--correlations with physical findings

The purpose of this study was to evaluate the influence of the graft positioning on the clinical outcome and magnetic resonance imaging (MRI) signal of the graft following anterior cruciate ligament (ACL) reconstruction using the central one-third of the patellar tendon. Twenty-two patients with a chronic anterior instability underwent a modified Marshall-MacIntosh procedure, while 27 with a subacute torn ACL had an ACL reconstruction using a free bone-patellar tendon-bone graft. The patients were retrospectively reviewed with a 1.8-year average follow-up (1-3 years). The clinical result was evaluated through the comparative range of motion and the residual laxity as measured with the KT 1,000 arthrometer. The roentgenographic analysis was performed from anteroposterior (AP) and mediolateral (ML) views, made first on one-leg standing with the knee at 30 degrees of flexion, and secondly at "zero" extension with active quadriceps contraction. Lines were drawn to visualise the location of the tibial and femoral tunnels in relation to the tibial plateaus and the intercondylar roof represented by Blumensaat's line. The analysis of the lateral MRI views of the graft allowed discrimination between homogenous and heterogenous graft signals. On lateral roentgenograms of normal knees, it was found that Blumensaat's line crossed the surface of the medial tibial plateau at 30% +/- 9% of its sagittal width (20%-40% range), demonstrating the variability of intercondylar roof inclination. The range of motion was normal in 34 patients (group I), 9 patients had a flexion deficit (group II), and 6 exhibited an extension deficit (group III). The residual laxity was similar in each group (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Ten-year survivorship of cemented ceramic-ceramic total hip prosthesis

In the first 187 consecutive alumina-alumina combination hip arthroplasties performed from 1977 to 1979, both components were cemented with conventional techniques. At ten-year follow-up evaluation, 87 patients were reviewed or interviewed by telephone, 37 were dead, 39 were lost to follow-up evaluation, and 24 failures were reoperated on before the end of ten years. The major cause of failure was aseptic loosening of the acetabular component (15 failures). Fracture of the socket and of the femoral head occurred in five patients in this series. However, these complications were not seen with components manufactured after 1979. At the end of ten years, survivorship analysis depicted a 82.59% survival rate when reoperation was considered as failure and a 88.57% rate when reoperation for aseptic loosening was considered as failure. The femoral component had a 99.16% survival rate and the acetabular component had an 88.57% survival rate when reoperation for aseptic loosening was considered as failure. Age, appearance of a two- or three-zone demarcation at the intermediate follow-up evaluation, and outer diameter of the acetabular component were the major parameters influencing the results. Better results observed in the population younger than 50 years of age may be related to the small amount of wear debris produced by the alumina-alumina combination. This combination in hip prosthesis is secure, but should be implanted in young and active patients; the outer diameter of the acetabular component must be at least 50 mm. The major problem that remains is the socket's fixation. It could be improved by a design modification, by choosing another mode of fixation, or both.

[Conflict between psoas and total hip prosthesis]

This conflict leads to a chronic irritation of the psoas by the antero-medial part of the cup, but it has been poorly described in the past. A study of six patients suffering from this trauma, and who were re-operated revealed that the muscle was worn thin in front of the prominent cup. In the case of 4 of the 6 patients pain had started to occur shortly after total hip replacement. The following symptoms were noted among all 6 patients: pain was suffered during flexion--extension movements--walking up stairs--arising from a chair. Pressure on the medial part of the groin was painful, especially during active elevation of the lower limb. Passive mobility was normal and painless. Psoas bursitis was observed in three cases. The main cause of this conflict is the protrusion of the cup beyond the antero-medial edge of the acetabulum; this protrusion may be either due to a bone graft or a bit of cement, but most often an acetabular insufficiency (congenital dysplasia) favors the formation of this anterior overhang. The spiral cup screwed into the bone can be especially aggressive when it protrudes. Treatment includes the resection of the overhang, but post-operative results will be uncertain unless the resection is really complete. In the case of 4 patients the results of such an intervention were only mild to poor. This problem can be avoided by proper care and preventive measures in the original replacement avoiding all projections beyond the anterior edge of the acetabulum--cup, bone graft, cement, especially if dysplasic.(ABSTRACT TRUNCATED AT 250 WORDS)

Alumina-on-alumina hip replacement. Results and survivorship in young patients

Total hip replacement using an alumina head and socket and a titanium alloy stem is evaluated in a series of patients under 50 years of age. Between April 1977 and December 1986, 86 such replacements were performed in 75 patients, but mainly because patients had difficulty travelling from Africa, only 71 hips were followed up adequately; of these, 56 were primary procedures and 15 revisions. Survivorship analysis showed that 98% of the prostheses were retained for 10 years. On clinical and radiological examination 51 of the 71 hips were stable and acceptable, 15 had radiological changes on the acetabular side, and one on the femoral side; four other cases had clinical and radiological changes suggesting impending failure, possibly because fixation of the socket was inadequate. There were no differences between the results of the primary procedures and those of revisions. In these young patients, the results seem better with alumina-on-alumina hips than with other varieties, possibly because of their remarkably low wear.

[The influence of the elasticity module of the femoral shaft and neck of a total hip prosthesis on the distribution of stress in the femur ]

Experiments have shown that stress shielding resulting from implantation of a prosthesis is related to the stiffness of the implant. Stiffness depends on the Young's modulus of the material used and the design of the implant. Most published studies have not attempted to define the relative importance of these two components. We have studied the influence of the elastic modulus only in an experiment using implants of a uniform design. Strain gauges were attached to the calcar in five femurs, three of which also had gauges placed on their medial, lateral and anterior aspects. Surface strain was measured in the intact femur and after implantation of cemented prostheses of the same design but manufactured with or without a collar in stainless steel or titanium alloy. The highest level of calcar strain was recorded with the titanium alloy prosthesis, and the presence of a collar appeared to increase the stress transfer of bone. This effect on stiffness was statistically significant, but was limited to the proximal part of the upper femur. It was not significant in the sub-trochanteric area, due to individual variations in bone geometry and cortical thickness. These results indicate that stress shielding can be directly related to the Young's modulus of the material used, independent of the design of the prosthesis.

The use of dense alumina-alumina ceramic combination in total hip replacement

The purpose of this article was to review the laboratory and clinical performances since 1970 of a total hip prosthesis using alumina-alumina combination. The chemical and physical properties of dense alumina ceramic were studied in relation to biocompatibility, mechanical strength, and surface properties. Through the examination of 35 retrieved implants, it was found that the long-term success of alumina-alumina total hip replacement depends on both the ceramic microstructure (small grain size with uniform distribution, minimum porosity, absence of inclusions) and implant geometry (sphericity deviation +/- 1 micron, radius tolerance between components 7-10 microns). Alumina component wear and fractures have disappeared with the use of high-performance materials and severe manufacturing quality control. Examination of human biopsies from well-fixed prostheses showed that alumina particles deposits increase with time with only a low-grade macrophagic reaction. When loosening occurred, an inflammatory reaction appeared; this reaction was less striking than with loose metal-polyethylene prostheses, however. The long-term behavior of cementless alumina cup fixation depends upon initial positioning and stability; survivorship analysis of the cemented ceramic cups showed an 88% survival probability after 8 years with a 1.6% average annual probability of revision. The percentage of surviving was 100% after 8 years in patients who were less than 50 years old. Aseptic loosenings occurring at the cup-cement interface were assumed to be related to stress protection secondary to the high rigidity of the ceramic leading to a weakening of the spongious bone supporting the cement mantle. Good bone stock quality as well as high-quality ceramic appear to be the prerequisites for durable fixation of alumina sockets.

Role of stem design and material on stress distributions in cemented total hip replacement

The risk of fatigue fractures of the femoral stem in a cemented total hip arthroplasty can be minimized by either increasing the stem cross-section and/or using a very high strength alloy. The object of this study was to compare important mechanical characteristics of five selected stem designs, differing in configuration and material (stainless steel, cast chrome cobalt alloy, nickel based alloy and titanium alloy). The stain pattern on the stem was analysed in a 3-point-bending jig and also after cementing it into cadaver femurs. Regardless of stem type or test method, the typical tensile stress distribution on the lateral stem was a bell shaped curve. For the cobalt-chrome and stainless steel stems, the larger the stem the lower were the stem stresses and the stress gradient, and the higher was the factor of safety. However, the factor of safety was increased even further by the use of super alloys such as MP35N and Ti6Al4V. In addition, Ti6Al4V alloy allowed the use of larger and stronger stems without the extra penalty of rigidity, which was enforced by either the steel or cobalt based alloy.

Spherocylindric (Luck) cup arthroplasty for osteonecrosis of the hip

Osteonecrosis (ON) in young adults is a serious condition causing pain and functional disability. Thirty-eight hips with ON were treated, beginning in 1972, with a spherocylindric cup (SCC) derived from the original Luck. The mean follow-up time was six years, 11 months (minimum, one year; maximum, 12 years). The overall results, using the Merle d'Aubigne grading system, were excellent in four, very good in nine, good in nine, fair in one, and failure in seven. No acetabular protrusio was observed. The seven failures were associated with deep infection in one case and unsatisfactory technique in three. One failure was unexplained, except that the ON was Grade IV. Two failures occurred in one patient with predisposing factors, such as hyperlipidemia, hyperuricemia, and exogenous hypercortisonism. Although the results are not as satisfactory as those of total hip arthroplasty (THA) with respect to relief of persistent pain, some patients remain stable with time even after more than ten years. With correct indications and good surgical technique, SCC arthroplasty is a justifiable alternative to THA in young adults.

Treatment of chronic anterior knee instabilities with combined intra- and extra-articular transfer augmented with carbon-PLA fibers

In the treatment of old chronic anterior knee instabilities by anterior cruciate ligament (ACL) insufficiency, isolated reconstruction of the ACL is insufficient because of an associated stretching of the lateral capsule and lateral collateral ligament. A combined intra- and extra-articular transfer (consisting of the central one-third of the patellar tendon, the prepatellar tissue, and the central one-third of the quadriceps tendon) is necessary to repair ACL instability. Augmentation of the autogenous transfer with polylactic acid-coated carbon fibers has several advantages. It improves the transfer's strength by reinforcing its weak zones; gives initial strength during graft remodeling and vascularization, thus avoiding cast immobilization; and allows early active rehabilitation and possibly return to sports activity. The surgical technique is based on biomechanical and biologic principles. The transfer remains attached to the tibial tubercle, passing through a tibial tunnel, through the intercondylar notch, behind the lateral femoral condyle in a bony groove, then on the lateral aspect of the condyle, beneath the lateral collateral ligament, and ending close to Gerdy's tubercle. The preliminary results in 30 patients are encouraging. The subjective and objective results are similar to those previously obtained with nonreinforced methods of repair, except that there is an early return to normal activities.

[Results of the surgical treatment of chronic external laxity of the ankle by resetting capsular ligamentous tension]

The authors review 12 patients operated for tibio-tarsal instability and summarize the effects of ligamentous sections of the capsular-ligamentous plane of the lateral part of the ankle and the importance of the anterior peroneotalar fascia. In cases of tibio-tarsal instability, the authors propose a lateral ligamentous re-tension plasty with trans-osseous reinsertion and they analyse the results of this operation in a series of 13 operated ankles which were followed clinically and radiologically. The essential criterion of evaluation was a return to the same level of sports activity (7 very good results, 3 good results, 2 moderate results and one failure). The overall favourable results suggest that this technique can be indicated in a number of rare cases: sportsmen with significant disability after failure of treatment by proprioceptive re-education. In conclusion, the authors stress the value of preventative treatment of sprained ankles, which should prevent the development of instability.

[Phosphorus metabolism in a case of tumoral calcinosis]

Hyperphosphataemia with levels of 65 mg/l was found in a black African aged 20 with a 10-year history of tumour calcinosis. Levels of blood calcium, plasma ionised calcium, serum alkaline phosphatase, 24-hour urinary calcium and phosphate were all normal, as was renal function. Tubular phosphate reabsorption (TmP) was greater than 90 mg per litre of glomerular filtrate (N = 22-42). Levels of circulating parathyroid hormone, nephrogenic cAMP and serum vitamin D metabolites [25 OH D3, 24,25 (OH)2 D3 and 1,25 (OH)2 D3] were normal. The TmP fell by 36% on exogenous PTH stimulation (N = 30.25 +/- 6.7), and by 7.9% 120 min. after injection of acetazolamide. Our results confirm the conclusions of recent studies: patients with tumour calcinosis have disordered renal phosphate excretion with normal PTH secretion, normal PTH action on the renal tubule and normal vitamin D metabolism. In fact in these hyperphosphataemic patients, circulating 1,25 (OH)2 D3 levels would be expected to be low, whereas they were normal in our patient. An attempt at treatment with acetazolamide and phosphate chelating agents gave no significant results.

[Benign osteoblastoma of the hand. A case report. Review of the literature]

One case of benign osteoblastoma, localized on the proximal phalanx of right thumb is reported. Three points are emphasized: the low frequency in the hand, only six observations are reported in the English literature, one by Jaffe (1932) and four by Lichtenstein (1964) and one from Mosher and coll. (1978). The non-specificity of the signs and X-ray are must consider chondroma, giant cell tumor, chondrosarcoma or aneurysmal cyst. The lesion is benign and so the treatment must be conservative.

[Results of direct surgery of the peroneal nerve in neuritis in Hansen's disease]

Twenty-two patients with common peroneal neuritis from Hansen's disease were treated surgically. Physiopathologic and semiologic features of the affection are discussed, as well as the rules for therapeutic protocols, which should involve both medical and surgical treatment, and the operative technique described. Results on motor function appear to be satisfactory, but are dependent on many factors (duration of the neuritis, importance of the compressive factor, immunopathological form of the disease, quality of medical treatment). The indications for these neurolytic procedures are defined, and are predominantly any hyperalgic deficiency neuritis. The only contraindications are chronic painless palsies where improvement is doubtful because of neural fibrosis.

Analyse du r�le m�canique des ligaments crois�s dans la laxit� ant�ropost�rieure du genou

In order to evaluate the contribution of both anterior (ACL) and posterior cruciate ligaments (PCL) in antero-posterior knee laxity, mechanical tests were performed on 31 fresh-cadaver-knees ranging from 20 to 68 years old. The joints flexed at 90 degrees in a mounting apparatus were placed in a testing machine with the tibia fixed in neutral rotation. The load-displacement curves were then analyzed. The results showed that the tensile strength of the ACL decreased greatly with age whereas its stiffness measured during anterior drawer test remained independent of age and sex. Successive resection of the antero-medial (AM) and postero-lateral (PL) bundles of the ACL demonstrated the AM bundle to be the major structure involved in the limitation of tibial displacement in the anterior drawer test. The amount of tibial shift during the anterior drawer test did not reflect the condition of the ACL, while its resection always induced a strong and significant drop in anterior knee stiffness. Dissection of the PCL was always followed by significant posterior tibial displacement during the posterior drawer test of over 10 mm, which did not permit the experimental apparatus to quantify the posterior load displacement relationship.

[Anomalies of division of the median nerve. A case. Review of the literature]

Abnormalities of division of the median nerve are exceptional. Several cases are found in the literature. The authors report a case of high bilateral division of the median nerve into two trunks of identical volume in a patient with Hansen's disease. The external trunk of the division supplies the thenar branch and the first commissure and the internal trunk supplies the second and third commissures.

[Primary malignant schwannoma of the hand. Apropos of a case. Review of the literature]

Primary malignant tumours of nerves stemming from Schwann cells are exceptional. One case of malignant schwannoma of a distal collateral nerve is reported. It would appear to be the first case. The elements of the histological diagnosis are recalled and the rules for treatment are advanced: wide excision involving, in this case, phalangeal amputation with a satisfactory result after one and a half years, with no local or loco-regional recurrence.

[Results of the surgical liberation of the ulnar nerve in retro-epitrochlear tunnel syndromes]

Three different techniques have been employed for surgical treatment of 62 ulnar nerves at the elbow region provoking neuropathies. Disorders became worse in 2 out of 11 patients treated by endofascicular neurolysis and this procedure should be abandoned. Overall sensory-motor results of subcutaneous anterior transposition of the nerve, performed in 26 cases, were inferior (78 p. cent good results) to those obtained by neurolysis combined with longitudinal epineurotomy (95 p. cent good results), applied in 25 cases. Almost constant disappearance of subjective symptoms, pain and paresthesia, was observed with the two latter methods. Treatment proposed for the ulnar tunnel syndrome is therefore simple neurolysis combined with longitudinal epineurotomy. Prognostic factors cannot be assessed from this study, the age, time between onset and operation, and the degree of paralysis having no incidence on the postoperative improvement obtained.

Capsular constriction of the hip: arthrographic and clinical considerations

Orthodox radiological examination of patients presenting with disorders of the hip, usually on account of pain and limitation of movement, may vary in diagnostic value. As a supplementary study we have employed arthrography. During this procedure we have, since 1970, routinely assessed the capacity of the joint capsule. The normal capacity varies from 20 ml in a large adult male to 14 ml in a small adult female. Significant reduction of this volume has been observed as a secondary complication of certain organic lesions, including four cases of synovial chondromatosis, one case of an intra-articular loose body, and one case of osteoid osteoma of femoral neck. In these secondary cases, the only common feature visible on the plain film was regional osteopenia. In these patients symptoms persisted until adequate surgical measures had been performed. (Descriptive term proposed: secondary capsular constriction of the hip: SCCH). In another group of seven patients, in whom orthodox radiological studies were unrewarding, arthrography was undertaken on account of persistent pain and limitation of movement. Similar reduction in the capacity of the joint was found, but in each case spontaneous resolution of the symptoms took place, without surgical intervention, in periods varying from three to 18 months. This self-limiting syndrome appears to be analogous to that of the "frozen shoulder" and, like the latter, is associated frequently with barbiturism.

[Diaphyseal bone tuberculosis]

The authors report a case of diaphyseal bony tuberculosis, in which the diagnosis was not made for a long time as bony tuberculosis is considered exceptional and owing to the presence of a staphylococcus which oriented the diagnosis towards osteomyelitis. Bony tuberculosis certainly affects more easily immigrant patients, in whom one may see multifocal forms, but also affects those who, by their environment, might imagine they are protected, and it is not exceptional to see unifocal forms.