Purpose: We compared three fixation systems for proximal fractures of the humerus to elaborate a rigid extra-medullary implant: the basket plate. This novel implant allows fixation of the tubercles with a claw system associated or not with a central cephalic locking screw. The objectives of this study were: check the resistance of the prototype, evaluate the contributions of the claws, and the usefulness of locking.

Material and methods: This was a prototype experimental study comparing a commonly used implant (Maconor2 plate) with the new implant using two series of static mechanical tests (Instrum). The tests were performed on 20 DMO-frozen anatomic specimens using the four-fragment fracture model. An implant was assigned to five groups of randomly selected specimens. The first tests (three groups) were axial compression tests mimicking abduction in the plane of the scaphoid. We analysed the overall mechanical behaviour of the implant and evaluated the locking system. The second tests (two groups) were traction tests. We analysed the behaviour of the fixed tuberosities. The mechanical resistance of the assemblies was noted as the limit load on the force: deformation curve and as the rigidity of the slope.

Results: The first tests showed that the implant was improved by the locking system and had better overall mechanical characteristics than the compared implant, although the difference was not statistically significant. The better hold in the tubercles provided by the claws was expected after the first tests and confirmed by the second tests, but the difference was not significant.

Discussion: The prototype improved with the locking system presented mechanical resistance equivalent to the compared model. The usefulness of locking could not be demonstrated but was considered to improve tolerance to loading by better force distribution. The contribution of the claws was not demonstrated statistically although the results are in line with early hopes. The present findings and data in the literature on shoulder biomechanics suggest that the tests should be conducted on a larger number of specimens to demonstrate a statistically significant difference. The tested series was too small.

Conclusion: Comparison of mechanical resistance with theoretical data on forces applied to the proximal humerus show that the prototype is well adapted, allowing immediate postoperative motion. A prospective study is currently being conducted in our unit.

Purpose: Continuous monitoring of the interstitial pressure of muscle compartments is a useful method for preventing compartment syndrome. The perfusion pressure is the key measurement (difference between the arterial diastolic pressure and the interstitial pressure). It should always remain above 30 mm Hg. Our postoperative monitoring data provided new insight into circumstances where there is a higher risk of compartment syndrome due to a fall in arterial diastolic pressure.

Material and methods: Twenty patients (13 boys and 7 girls) underwent continuous monitoring of the interstitial pressure of the anterolateral compartment of the lower limb. These children had undergone lengthening-realignment procedures, realignment procedures, or treatment of fracture. Mean age was 11.5 years. Preventive subcutaneous aponeurotomy was performed in 15 patients. The patients were monitored for a mean 55 hours. The interstitial pressure was noted every hour, in addition to pain on a visual scale, and the type and administration route of antalgesics. A risk condition was defined as perfusion pressure (diastolic arterial pressure – interstitial pressure) less than 30 mmHg.

Results: One or more episodes of low perfusion pressure (< 30 mmHg) were observed in eleven of the twenty patients, during the first five postoperative hours in five and during sleep and awakening phases in eight. Pain was not increased during these periods during which antalgesics were administered. The common denominator for these risk conditions was high pressure in the muscle compartment but low diastolic pressure. None of the children developed a compartment syndrome with sequela. Preventive aponeurotomy did not protect against the development of these risk conditions.

Discussion: These results provide new insight into the haemodynamic conditions occurring during the recovery period and point out the need for rapid recovery of an elevated diastolic arterial pressure. This would decrease the risk of compartment syndrome and also limit postoperative oedema.

Conclusion: Immediate postoperative monitoring of the interstitial pressure demonstrated that the risk of compartment syndrome occurs when the diastolic pressure is low, that is during postoperative awakening and periods of sleep in children given antalgesics.

Purpose of the study: The aim of this work was to report our experience with arthroscopy for the treatment of acetabular labral lesions and identify prognostic factors determining mid- and long-term outcome.

Material and methods: Between August 1991 and December 1997, 12 patients (ten women, two men, mean age 39 years, age range 25–61 years) underwent arthroscopic treatment of an acetabular labrum lesion. All were reviewed at a mean 4 years follow-up (18 months-8 years). Half of the patients (n = 6) had a history of hip surgery: two femoral osteotomies and one acetabular bone block for congenital hip dislocation, two high-energy traumas and one traumatic dislocation. Clinical manifestations including pain (n = 12), a sensation of a snag (n = 10), or blockage (n = 8) had developed over a mean 15 months (2–24 months). Standard x-rays evidenced early signs of degenerative disease in four cases and acetabular dysplasia in four (5° < VCE < 18°), and were normal in four. Arthroscanography was performed in all cases and always evidenced a lesion of the anterior or anterosuperior part of the labrum, generally a fissuration (n = 7). The surgical procedure performed on an orthopedic table with traction on the limb lasted 45 to 75 min for regularization of the degenerated labrum in three patients, resection of the languette in six, the anse de seau in two or the labral notch in one. A short hospitalization (24 to 48 hours) was sufficient with immediate weight bearing with two canes. One patient developed sciatic paresia which regressed in 72 hours with vulvar edema due to excessive peroperative traction.

Results: Besides the labral lesion, the exploration also identified an associated chondral lesion in seven cases (acetabulum in two, femoral head in three, both in two) which had been suspected in six cases from preoperative imaging (osteoarthrosis in four, dysplasia in two) and which affected the final outcome. Four of these patients (osteoarthritis in two and dysplasia in two) worsened clinically and radiographically to the point where a total hip arthroplasty was required in three. Among the three other patients, two had residual pain (osteoarthritis in one and initial x-ray normal in one) with no radiographic deterioration and only one (osteoarthrtis) was totally relieved without any radiographic deterioration at six years follow-up. Among the five patients with no chondral lesions, three (with normal x-rays initially) were pain free at four years follow-up while the two others (dysplasia) had residual pain at two years follow-up with no sign of osteoarthrtis on the latest x-rays.

Discussion: Lesions of the acetabular labrum are uncommon but can be treated arthroscopically. Resection of the labral lesion is immediately effective but does not prevent long-term degradation of the joint if there is an associated chondral lesion.

We present an original method for the treatment of neglected Monteggia fractures using the Ilizarov technique. This method allows reduction without accessing the radial head by progressive ulnar lengthening after proximal subperiosteal osteotomy of the ulnar bone. We used this method in a six and a half year old girl and achieved excellent radiographical and functional results with normal joint amplitudes. In our opinion, the quality of the outcome is related to the progressiveness of the bone lengthening enabled by this technique which allows restoration of the ulnar length, preservation of the axes of both forearm bones, and controlled reduction of the radial head.