3D templating and patient-specific cutting guides (Knee-Plan) in total knee arthroplasty: postoperative CT-based assessment of implant positioning

INTRODUCTION

The precision of bone cuts and the positioning of components influence the functionality and longevity of total knee arthroplasty (TKA). The objective of this study was to evaluate the results of TKA, performed after 3D preoperative templating, with the prosthesis implanted using custom cutting guides (Knee-Plan system, Symbios Orthopédie SA).

MATERIAL AND METHODS

This prospective study investigated 107 TKAs. Three-dimensional preoperative templating was carried out on the surface views and CT views to analyze the deformation of the lower limb and plan the implantation. The components were positioned in an individualized manner to realign the lower limb and provide ligament balance based on bone landmarks. Final component positioning was analyzed in the three planes with a postoperative CT scan. The preoperative and 1 year follow-up IKS and WOMAC scores were collected and compared.

RESULTS

All the cutting guides were stable and functional. Femoral component planning was reproduced with 0 ± 2 precision in the frontal plane (94%± 3), 2 ± 3 in the sagittal plane, and 0 ± 2 in the transverse plane. The precision of the tibial component was reproduced with 0 ± 2 precision in the frontal plane (93%± 3) and 0 ± 4 in the sagittal plane. The HKA angle increased from 177 ± 7 preoperatively to 180 ± 3 at 1 year of follow-up. The IKS and WOMAC scores were significantly improved at 1 year (P<0.0001).

CONCLUSION

The Knee-Plan system can be a realistic, simple, and reliable alternative to conventional cutting guides and to computer-assisted surgery for TKA implantation.

LEVEL OF EVIDENCE

IV; prospective cohort study.

Surgical treatment of patellar tendinopathy in athletes. A retrospective multicentric study

The purpose of this study was to evaluate the results of surgery, in particular arthroscopic procedures in the treatment of patellar tendinopathies that are refractory to conservative treatment in athletes.

METHOD

A retrospective multicenter study was performed in four centers. Patients were athletes who did not respond to carefully followed conservative treatment and who underwent surgery. Sixty-four patients were included, 10 who underwent arthroscopy. Patients were questioned and followed-up for an average of 22 months (6-116 months).

RESULTS

At the final follow-up, 87% of the patients had an improved Blazina score and 63% were again practicing their sport at the same level. None of the preoperative factors influenced the final result and one surgical technique was not more effective than another (patellar tip resection versus arthroscopic approach).

DISCUSSION

The results of this study are comparable to those in the literature which show a success rate of more than 80% whatever the surgical technique. This study limits a certain number of biases because the patient group is homogenous (athletes, unsuccessful conservative treatment) with similar functional scores, and well-defined protocols for postoperative rehabilitation. However, the study of this entity is difficult because of the limited number of subjects and its different anatomopathological forms.

CONCLUSION

Surgical treatment is indicated in motivated athletes if carefully followed conservative treatment is unsuccessful after more than six months, making it impossible to practice a sport (Blazina grade 3). Arthroscopic techniques seem to be as effective as open surgery with an equivalent delay for beginning sports activities.

In vitro comparison of human fibroblasts from intact and ruptured ACL for use in tissue engineering

The present study compares fibroblasts extracted from intact and ruptured human anterior cruciate ligaments (ACL) for creation of a tissue engineered ACL-construct, made of porcine small intestinal submucosal extracellular matrix (SIS-ECM) seeded with these ACL cells. The comparison is based on histological, immunohistochemical and RT-PCR analyses. Differences were observed between cells in a ruptured ACL (rACL) and cells in an intact ACL (iACL), particularly with regard to the expression of integrin subunits and smooth muscle actin (SMA). Despite these differences in the cell source, both cell populations behaved similarly when seeded on an SIS-ECM scaffold, with similar cell morphology, connective tissue organization and composition, SMA and integrin expression. This study shows the usefulness of naturally occurring scaffolds such as SIS-ECM for the study of cell behaviour in vitro, and illustrates the possibility to use autologous cells extracted from ruptured ACL biopsies as a source for tissue engineered ACL constructs.

["Isolated" injury of the posterior cruciate ligament. Surgical treatment of isolated posterior cruciate ligament tears: a multicentric retrospective study of 103 patients]

PURPOSE OF THE STUDY

We present a retrospective multicentric series of carefully selected patients presenting "isolated" laxity of the posterior cruciate ligament.

MATERIAL AND METHODS

The series included 103 patients who were reviewed clinically (with a dedicated review chart) and radiographically with measurement of posterior laxity (Telos 15 kg).

RESULTS

In these patients with an isolated injury of the PCL (without associated injury of the peripheral ligament)

DISCUSSION

The short follow-up of this series (four years) does not enable an assessment of the risk or benefit of PCL ligamentoplasty for arthrosic knees.

[Focused lithotripsy in the treatment of tendinosis calcarea of the shoulder: results at 2 months and one year]

OBJECTIVE

The authors report their experience with extracorporeal lithotripsy in 30 patients with calcific tendinosis of the rotator cuff.

MATERIALS AND METHOD

This technique is based upon the utilization of high-energy shockwaves (6000 shocks in 3 sessions Day 1, D8, D30) under continuous ultrasound localization of the lesion (EPOS Ultra1). Calcification were evaluated at plain film, US and CT to characterize their length and features.

RESULTS

Complete or partial resorption of calcifying deposits within 2 months and one year was observed in 27.5% and 25% of cases respectively. Clinical improvement results are encouraging at two months (50%), but reduced at one year (28.5%), consistent with the rate of resorption of calcifications.

CONCLUSION

This painful, long, and expensive technique seems to be disappointing in the treatment of the calcific tendinosis.

Sensori-motor adaptation to knee osteoarthritis during stepping-down before and after total knee replacement

Background

Stepping-down is preceded by a shift of the center of mass towards the supporting side and forward. The ability to control both balance and lower limb movement was investigated in knee osteoarthritis patients before and after surgery. It was hypothesized that pain rather than knee joint mobility affects the coordination between balance and movement control.

Methods

The experiment was performed with 25 adult individuals. Eleven were osteoarthritic patients with damage restricted to one lower limb (8 right leg and 3 left leg). Subjects were recruited within two weeks before total knee replacement by the same orthopedic surgeon using the same prosthesis and technics of surgery. Osteoarthritic patients were tested before total knee replacement (pre-surgery session) and then, 9 of the 11 patients were tested one year after the surgery when re-educative training was completed (post-surgery session). 14 adult individuals (men: n = 7 and women: n = 7) were tested as the control group.

Results

The way in which the center of mass shift forward and toward the supporting side is initiated (timing and amplitude) did not vary within patients before and after surgery. In addition knee joint range of motion of the leading leg remained close to normal before and after surgery. However, the relative timing between both postural and movement phases was modified for the osteoarthritis supporting leg (unusual strategy for stepping-down) before surgery. The "coordinated" control of balance and movement turned to be a "sequential" mode of control; once the body weight transfer has been completed, the movement onset is triggered. This strategy could be aimed at shortening the duration-time supporting on the painful limb. However no such compensatory response was observed.

Conclusion

The change in the strategy used when supporting on the arthritis and painful limb could result from the action of nociceptors that lead to increased proprioceptor thresholds, thus gating the proprioceptive inputs that may be the critical afferents in controlling the timing of the coordination between balance and movement initiation control.

Reconstruction du ligament croisé antérieur par greffe de tendons de la patte d’oie à un ou à deux faisceaux

PURPOSE OF THE STUDY

We worked with cadaver specimens to evaluate control of anterior knee laxity after reconstruction of the anterior cruciate ligament (ACL) comparing double two-strand anterolateral and posteromedial reconstruction with the classical four-strand technique. We hypothesized that the double reconstruction would provide better control of anterior laxity in both flexion and extension.

MATERIAL AND METHODS

Sixteen cadaver knees were randomly assigned to reconstruction technique. Anterior tibial translation was measured with an arthrometer (Rolimeter) at maximal manual tension at 20 degrees, 60 degrees and 90 degrees flexion on the intact knee, after section of the ACL and after arthroscopic reconstruction using either the classical four-strand hamstring technique or a double two-strand anteromedial and posterolateral technique. An EndoButtonCL was used for the femoral fixation and a interference screw with staples for the tibial fixation. Variation in the length of each construct was measured between 0 degrees and 90 degrees flexion.

RESULTS

In the single reconstruction group, the length of the graft varied by 0.5 +/- 0.7 mm between 0 degrees and 90 degrees flexion. In the double reconstruction group, the length varied by 0.5 +/- 0.9 mm for the anteromedial construct and 3.4 +/- 0.5 mm for the posterolateral construct. When studied with an intact ACL, anterior laxity of the 16 knees was 3.2 +/- 1.1, 3.5 +/- 1.5 and 2.6 +/- 1.1 mm at 20 degrees, 60 degrees, and 90 degrees respectively. After section of the ACL, laxity increased significantly at all angles: 9.4 +/- 3.3, 6.1 +/- 2.5 and 6.8 +/- 2.9 at 20 degrees, 60 degrees, and 90 degrees respectively. After classical four-strand single graft reconstruction, the residual anterior laxity was 3.7 +/- 0.9, 3.1 +/- 1.1, and 2.3 +/- 1.6 mm at 20 degrees, 60 degrees, and 90 degrees flexion. Statistical analysis using parametric or non-parametric tests as appropriate showed a significant difference in laxity at 20 degrees, 60 degrees, and 90 degrees of flexion between knees with a cut ACL and knees with reconstructed ACL. At 20 degrees flexion, residual laxity was greater after single-construct reconstruction. At 60 degrees and 90 degrees there was no significant difference in anterior translation of the tibia in knees with intact or reconstructed ACL. After reconstruction with the dual-construct technique, laxity was 3.4 +/- 1.3, 2.6 +/- 1.5, and 2.4 +/- 1.2 mm at 20 degrees, 60 degrees and 90 degrees flexion respectively. Laxity was significantly greater with a cut ACL than after reconstruction at 20 degrees, 60 degrees, and 90 degrees flexion, but there was no significant difference in anterior translation of the tibia at 20 degrees, 60 degrees, and 90 degrees flexion between knees with an intact and a reconstructed ACL.

DISCUSSION

These results based on a clinical evaluation measuring anterior translation of the tibia with an arthrometer are in agreement with results in the literature using robots. Compared with the classical technique, reconstruction of the ACL with a dual-construct technique provides a statistically significant improvement in control of anterior tibial translation at 20 degrees of flexion. The advantage of the dual anteromedial and posteriolateral construct technique is thus not found in the control of anterior laxity but rather in control of rotation laxity.

CONCLUSION

Reconstruction of the ACL with a two-bundle graft technique provides control of anterior laxity at 20 degrees, 60 degrees, and 90 degrees flexion similar to that observed in knees with an intact ACL while the single construct technique re-establishes physiological laxity at 60 degrees and 90 degrees only. This improved control of anterior laxity with the two-bundle reconstruction is a small improvement regarding anterior laxity, the more potential advantage concerning rotational stability.

[Biomechanical consequences of a knee osteoarthritis on the opposite lower limb]

The aim of this work was to study the compensatory strategies built up by patients with unilateral knee arthritis during stair descent. These compensatory strategies might induce increased biomechanical constraints on the unaffected knee.

METHOD

A kinetic and kinematic analysis was performed in 11 patients with unilateral knee arthritis and in 14 control subjects using an ELITE system and two force-plates. The peak of vertical ground reaction forces when landing on the reception force-plate, the time to reach the peak and the duration of the different phases of the movement were studied during stair descent.

RESULTS

The peak of vertical ground reaction forces was more important when landing on the unaffected limb than when landing on the affected limb. The time to reach this peak was longer in patients than in controls no matter which side was supporting. The duration of the single support phase was longer on the unaffected limb than on the affected limb.

DISCUSSION AND CONCLUSION

This work has shown that patients with unilateral knee arthritis develop new strategies during stair descent. These new strategies imply increased biomechanical constraints on the unaffected limb and might favor arthritis on the sound side. These results support the idea that rehabilitation protocols of patients with unilateral knee arthritis should also involve the unaffected limb.

[Arthroscopic reconstruction of the anterior cruciate ligament using double anteromedial and posterolateral bundles]

We propose a method for repairing the anterior cruciate ligament which takes advantage of the multifascular nature of the ligament to achieve better physiological anteroposterior and rotational stability compared with conventional methods. Arthroscopic reconstruction of the anteromedial and posterolateral bundles of the ligament closely reproduces normal anatomy. We have used this technique in 92 patients with anterior cruciate ligament laxity and present here the mid-term results. The hamstring tendons (gracilis and semitendinosus) are harvested carefully to obtain good quality grafts. Arthroscopic preparation of the notch allows careful cleaning of the axial aspect of the lateral condyle; it is crucial to well visualize the region over the top and delimit the 9 h-12 h zone for the right knee or the 12-15 h zone for the left knee. The femoral end of the anteromedial tunnel lies close to the floor of the intercondylar notch, 5 to 10 mm in front of the posterior border of the lateral condyle, at 13 h for the left knee and 11 h for the right knee. The femoral end of the posterolateral tunnel lies more anteriorly, at 14 h for the left knee and 10 h for the right knee. The tibial end of the posterolateral tunnel faces the anterolateral spike of the tibia. The tibial end of the anteromedial tunnel lies in front of the apex of the two tibial spikes half way between the anteromedial spike and the anterolateral spike, 8 mm in front of the protrusion of the posteriolateral pin. The posterolateral graft is run through the femoral and tibial tunnels first. A cortical fixation is used for the femoral end. The femoral end of the anteromedial graft is then fixed in the same way. The tibial fixation begins with the posterolateral graft with the knee close to full extension. The anteromedial graft is fixed with the knee in 90 degrees flexion. Thirty patients were reviewed at least six months after the procedure. Mean age was 28.2 years. Mean overall IKDC score was 86% (36% A and 50% B). Gain in laxity was significant: 6.53 preoperatively and 2.1 postoperatively. Most of the patients (86.6%) were able to resume their former occupation 2 months after the procedure. The different components of the anterior cruciate ligament and their respective functions have been the object of several studies. The anteromedial bundle maintains joint stability during extension and anteroposterior stability during flexion. The posterolateral bundle contributes to the action of the anteromedial bundle with an additional effect due to its position: rotational stability during flexion. In light of the multifascicular nature of the anterior cruciate ligament and the residual rotational laxity observed after conventional repair, our proposed method provides a more anatomic reconstruction which achieves better correction of anteroposterior and rotational stability. This technique should be validated with comparative trials against currently employed methods.

Reorganization of equilibrium and movement control strategies after total knee arthroplasty

This work was aimed at identifying changes in posturomotor control strategies in patients with unilateral total knee arthroplasty. Using kinetic and kinematic data, a previous study had revealed that, during a side step, patients with unilateral knee arthritis showed a shortened monopodal phase and a lengthened postural phase when the affected leg was the supporting one. It was expected that these strategies would be modified after undergoing total knee arthroplasty. Postoperatively the durations of the monopodal phase and of the postural phase became similar when the operated limb was supporting and when the sound limb was supporting. Concerning the upper body movements, the same asymmetrical results as before surgery were observed. Hence, patients with total knee arthroplasty exhibit posturomotor strategies which, although they become close to normal, remain asymmetrical. The durations of the monopodal and of the postural phases could be considered to assess the results of total knee arthroplasty.

Asymmetry of gait initiation in patients with unilateral knee arthritis

OBJECTIVE

To identify how patients with knee arthritis modify their equilibrium and movement control strategies during gait initiation.

DESIGN

Observational study.

SETTING

University hospital movement analysis laboratory.

PARTICIPANTS

Twelve patients with unilateral knee arthritis and 12 healthy control subjects.

MAIN OUTCOME MEASURES

Durations of the phases of gait initiation (ie, postural, monopodal, and double-support phases), center-of-pressure displacements, ground reaction forces, pelvic velocity, step length, and knee range of motion were measured using a movement analysis system and force plates.

RESULTS

Gait initiation was slower in patients than in controls no matter which leg was the supporting one. In patients, the durations of the postural and the monopodal phases were modified in an asymmetrical way according to the leg used as the supporting one. The postural phase was lengthened and the monopodal phase was shortened when the affected leg was the supporting one. Opposite effects were observed when the sound leg was supporting. Step length, knee range of motion, and maximal pelvic velocity were reduced in patients whatever the side of the supporting leg.

CONCLUSION

Gait initiation is an asymmetrical process in unilateral knee arthritis patients, who develop adaptive posturomotor strategies that shorten the monopodal phase on the affected leg.

[Isokinetic comparative study at the third postoperative month after surgery of the anterior cruciate ligament with arthroscopy or after mini-arthrotomy]

PURPOSE

A double blind prospective study was performed in 64 patients with a clinical and isokinetic assessment three months after anterior cruciate ligament (A.C.L.) reconstruction.

MATERIAL AND METHODS

This work included 64 patients (47 males and 17 females), divided in two groups: 41 patients had an arthroscopically assisted bone-tendon-bone A.C.L. reconstruction, 17 had an open procedure. The isokinetic records concerned peak torque and muscular work at two different speeds.

RESULTS

Three months after surgery there was no significant difference between both groups particularly what concerns the isokinetic assessment in muscular performances. Peak torque in hamstring averaged 151.4 Nm in the open procedure group and 149.2 Nm in the arthroscopically assisted group (p = 0.7), in quadriceps 156.10 Nm vs 149.3 Nm (p = 0.47).

DISCUSSION

The advantages of arthroscopy in early muscular recovery are rarely admitted in medical literature.

CONCLUSIONS

The favorable opinion of the authors to the arthroscopically assisted A.C.L. reconstruction concerning its rapid muscular recovery abilities is only based on subjective criterions.

[Traumatic ruptures of the pectoralis major muscle. Apropos of 3 cases]

INTRODUCTION

Three ruptures of the pectoralis major are reported. The mechanism of injury was excessive external rotation with high muscular tension. Rupture of muscle often occurs at the humeral insertion or musculotendinous junction.

MATERIAL AND METHODS

In the three cases, surgical repair was performed. Suture could be made without excessive tension. Patients were immobilized in a sling for three weeks. Passive exercises were begun at 3 weeks.

RESULTS

All patients recovered and had postoperatively the same sport level as before. In late surgical repair the consistent fibrosis makes dissection of the ruptured tendon difficult and it's retraction hinders the suture.

DISCUSSION

The symptoms are sometimes initially under evaluated. In limited number of cases the treatment may be delayed: functional disability and strength limitation justify surgical treatment. The results, however, are usually good according to the score of Mc Entire. Surgical repair is recommended in distal ruptures in active patients to restore previous muscle strength and contour.

[Influence of knee replacement arthroplasty on modalities of weight transfer during the lateral step]

INTRODUCTION

The aim of this work was to study the relations between equilibrium and movement in patients after total knee arthroplasty. A previous study, conducted in patients with unilateral knee osteoarthritis, had shown that the timing of the events occurring during a side-step was modified in an asymmetrical way according to the supporting leg with respect to the affected one.

METHOD

A kinetic and kinematic analysis was performed in a population of 9 patients before and after total knee arthroplasty and in 11 control subjects, using an ELITE system and two AMTI force-plates. The different phases (i.e. postural, monopodal, landing and stabilization) of a side step were studied.

RESULTS AND DISCUSSION

Before surgery, the postural phase was longer and the monopodal phase was shorter in knee arthritis patients when the affected leg was the supporting one than when the sound leg was supporting. Total step duration and landing-stabilization phase duration were longer in patients no matter which leg was supporting than in control subjects. After total knee arthroplasty, the postural phase remained longer when the operated leg was supporting than when the sound leg was supporting. Altered proprioception can provide an explanation for this result. However, the duration of the postural phase decreased significantly when the operated leg was supporting as compared to when the affected leg was supporting before surgery. The duration of the monopodal phase was the same when the operated leg was supporting than when the sound limb was supporting and increased significantly as compared to when the affected leg was supporting before surgery. This result can be related to the decrease of pain which was observed in all patients after surgery. The duration of the landing-stabilization phase and the total movement duration remained longer in patients after surgery no matter which leg was supporting than in control subjects.

CONCLUSION

This study shows that relations between equilibrium and movement tend to become symmetrical with respect to the leg used as supporting one in patients after undergoing total knee arthroplasty but remain different from those of control subjects. This movement analysis method enables to determine and to quantify differences in patients before and after undergoing total knee arthroplasty and thus provides additional information for the functional evaluation of patients with total knee prosthesis.

Surgical management of calcific tendinitis of the shoulder: an analysis of 26 cases

Chronic calcific tendinitis of the shoulder has good results after medical treatment in most cases. Around 10% of the patients resistant to medical treatment require surgery. We report 22 patients operated on using an open procedure. The operation included removal of the calcific deposit and an acromioplasty. The patients were rated preoperatively and postoperatively for pain, limitations in activities of daily living, range of movement and power according to a questionnaire and the Constant assessment. Globally the average score increased from 52.2 points out of 100 at the preoperative examination to 89.3 postoperatively with a mean follow up of 23 months. The most favourable results are obtained in patients with the longest interval between onset of disease and intervention (over 1 year) and with a progressive course of disease. Different techniques are discussed. Arthroscopically assisted procedures and open techniques are compared.

Reorganization of equilibrium and movement control strategies in patients with knee arthritis

The purpose of this study was to identify changes in equilibrium and movement control strategies in patients with arthritis of the knee. These strategies were expected to be different from those of healthy subjects because of the impairments caused by knee arthritis. The different phases of a side step were studied in patients with severe knee arthritis using a movement analysis system and force-plates. The duration of the postural phase and the intensity of the horizontal ground reaction forces during the postural phase were increased when the pathological limb was the supporting one. The monopodal phase was shortened on the pathological leg. These results show that knee arthritis patients develop new posturomotor strategies mainly aimed at shortening the monopodal phase when the affected leg is the supporting one. This movement analysis method enables quantification of differences that cannot be observed on clinical examination between knee arthritis patients and control subjects, and provides additional information to the usual clinical evaluation scales.

[Methods of shifting body weight in patients with knee arthroses]

INTRODUCTION

The aim of this work was to study movement control strategies in patients with knee arthritis. These strategies were expected to be different from healthy subjects because of deficiencies due to knee arthritis (i.e. pain, altered proprioception).

METHOD

A kinetic and kinematic analysis was performed in a population of 10 patients with unilateral knee arthritis and in 11 age-matched control subjects, using an ELITE system and two AMTI force-plates. The different phases of a side step were studied.

RESULTS

The timing of the movement was different in the two populations. The postural phase was longer and the monopodal phase was shorter in knee arthritis patients when the affected leg was the supporting one than when the sound leg was supporting. Total step duration and landing-stabilization phase duration were longer in knee arthritis patients than in healthy subjects.

CONCLUSION

This movement analysis method enables to determine and to quantify differences between knee arthritis patients and control subjects. Clinical examination cannot identify these differences. Movement analysis methods bring up additional information to usual clinical evaluation scales and could be used for evaluation of the results of total knee arthroplasty.

[Pigmented villonodular synovitis of the knee. Treatment results in 22 cases]

PURPOSE OF THE STUDY

The authors report their experience about 22 cases of pigmented villonodular synovitis of the knee observed between 1970 and 1997. The authors studied the results of treatments according to localization, evolutionary stage and condition of an early diagnosis.

MATERIAL AND METHODS

Among thirty three cases of pigmented villonodular synovitis treated during the same period the knee was involved in twenty two cases. Diagnosis was done or highly suspected in 13 cases because of significant symptoms (iterative hemarthrosis, bony gap in both articular components of the joint) or by MRI. The biopsy performed in each case allowed histological assessment in 22 patients. Surgical treatment was achieved in 19 patients. Three knees were not operated (two patients refused; one had a synoviorthesis) the treatment was a synovectomy alone for fifteen patients; four patients, needed a knee prosthesis, because of important degenerative joint disease.

RESULTS

Fourteen patients, with a mean follow-up of five years were reviewed. Four had a recurrence which appeared between three and eight years after subtotal synovectomy for diffuse synovitis. There were no recurrence after arthroplastic treatment and in localized lesions.

DISCUSSION

Pigmented villonodular synovitis should be treated as soon as possible but its different clinical features make diagnosis sometimes difficult. Because of an aggressive tendency of the disease which finds expression in extensive lesions in joint and bone, and early diagnosis allowed by MRI could make the prognosis more favourable.

CONCLUSION

Surgical synovectomy is the usual treatment. In evolved stages arthroplasties are performed. Localized lesions and recurrences should need arthroscopic treatment.

Anterior cruciate ligament reconstruction by mini-arthrotomy

We present 50 consecutive patients with chronic anterior cruciate deficiency treated by reconstruction of the ligament through a limited arthrotomy using the middle third of the patellar tendon as a graft. The patients were all men with a mean age of 26 years (range 17 to 36 years) with an average follow up of 24 months. There were good or excellent results as measured by the Lysholm score in 41, and in 27 with the ARPEGE score. Movements were full in 46 and retropatellar pain was experienced by 4.

[Coraco-trochineal conflict or anteromedial conflict of the shoulder. Contribution of arthroscanners]

Like the anterosuperior subracromial conflict, the coracotrochineal or anteromedial conflict of the shoulder is a groove pathology. In a series of 340 patients who had an arthroscan of the shoulder, including 245 with a conflict syndrome (70%), we observed an anteromedial conflict in 12 cases (8.5%) of the 140 patients with an intact cuff and 52 cases (50%) in 102 patients with an injured cuff. The frequency of the anteromedial conflict appears to be proportional to the degree of cuff injury. We described the signs of the trochin suggesting the anterior musculotendinous structures (subscapsular tendon and/or long biceps tendon) are involved and conclude that the anteromedial conflict is often misdiagnosed. It would appear to be a frequent complication of cuff injury (mechanical theory) which the surgeon should take into consideration when repairing cuff injury.

[Surgical treatment of ruptures of the rotator cuff]

This study analyses the results of 30 surgical repairs of the rotator cuff. The basic problem was degenerative pathology in which medical treatment had been tried previously in all cases. The type of treatment was based upon preoperative evaluation and arthro-CT scan in particular. Results were invariably good, with regression of pain and recovery of activity. Muscle power was significantly correlated with the value of the tendon repaired, this being reflected overall by incomplete recovery.

[Bacillary trochanteritis. Apropos of 30 cases]

Tuberculous trochanteritis is rare. The authors report 30 cases, 2/3 of which were seen in sanatoria. They occurred in four cases out of five in patients with long standing tuberculosis but were sometimes the presenting feature. Development of an abscess of the trochanteric serous bursa is a virtually constant complication. Their minimal functional consequences and slow progression endow them with an apparently benign nature which masks the risk of secondary complications (4 cases of coxalgia). Radiological appearances, minimal in early forms, are currently becoming more abundant by virtue of new medical imaging techniques. Specific antibiotic therapy is adequate in two cases out of three, completed in advanced and aggressive forms by local procedures dominated by surgical excision (13 cases).

[Hemopigmented villonodular synovitis]

Pigmented Villonodular Synovitis (PVNS) in an infrequent tumoral like disease and there are only a few MRI studies published. Concerning our series of five cases compared with the literature, the readers attention is drawn to the etiologies still under debate and to the respective contribution of the different imaging methods. MRI known for its high sensibility, but also for its low specificity in tumoral pathology, has turned out to be, in the case of PVNS, quite remarkable in both regards. The RMI aspect is quite well correlated to the histological structure of this synovial hyperplasia and to its evolution: highly vascular mass at the beginning and then low cellular density stroma, fibrous, with deposition of hemosiderin. In our five cases, as in almost all those previously reported in the literature, MR imaging shows heterogeneous areas of decreased signal intensity on T2 weighted sequences and on two of our cases after administration of gadolinium. Still the same MR aspects can be found in rheumatoid, hemophilic arthritis, as well as synovial chondromatosis, and therefore the clinical background and findings as well as plain films become essential. MR imaging should be the first examination to be undertaken after plain films, leading in most cases to a precise local preoperative assessment.

[Value of the technique of cellular lysis by thermic shock in the isolation of bacteria causing osteoarticular infections]

The purpose of this work is to compare, a conventional technique, for bacterial isolation, with a lysis-centrifugation method using a rapid freezing in liquid nitrogen, followed by decongelation at 37 degrees C for bone and joint samples. The bone and joint specimens were biopsies and punctions (35 cases) or fistula (10 cases). The residual antibiotic activity of the sample was determined using a susceptible strain of Micrococcus luteus and of Staphylococcus epidermidis. Among the 45 samples, 20 were sterile with both methods among which 8 exhibited a residual antibiotic activity which may have contributed to isolation failure. In 12 cases, bacterial isolates were obtained with both methods. Cultures were obtained from 13 samples with the lysis centrifugation method alone. The isolates were 4 Staphylococcus aureus, 8 coagulase-negative Staphylococcus and 1 Acinetobacter sp. These results suggest that the intracellular location of bacteria may be responsible for the negative cultures from bone or joint specimens.

[Pigmented villonodular synovitis of joints. Apropos of 16 cases. Surgical aspects. Contribution of nuclear magnetic resonance imaging]

This study of 16 cases of pigmented villonodular synovitis of joints treated by the same surgical team involved 6 cases of the localized or nodular form and 10 cases of the diffuse form. The knee was the commonest joint involved (12 cases), with involvement of the hip (3 cases) and foot (1 case) being rarer. Bone invasion is usual when the joint is narrow (hip, foot) but is rarer in the knee where joint capacity is greater (5 cases out of 12). Clinical symptomatology is rarely typical. Hemarthrosis, the most suggestive sign, was found in only two cases out of twelve. While the final diagnosis must always be based upon histology, great help may be provided by modern techniques such as arthroscopy, computed tomography and above all MRI, the presence of hemosiderin being shown by a low signal in T1 which decreases even further in T2. Treatment is based upon surgical synovectomy, with advanced osteoarticular lesions requiring joint replacement.