Aim

Shoulder prosthesis chronic infection is a rare but serious complication, likely to lead to re-interventions and poor functional outcome. Two-stage exchange surgery is considered the standard procedure by most authors.

Our hypothesis was that one-stage revision procedure is a valid therapeutic option in the management of chronic infections of shoulder arthroplasty.

BACKGROUND:

Bony healing of tuberosities around shoulder prostheses is difficult to obtain in the elderly patient. We hypothesized that reattachment of the tuberosities, performed in combination with bone grafting, around a specific reverse shoulder fracture-prosthesis (RSFP) would favour improved tuberosity healing and shoulder mobility in elderly patients with displaced proximal humerus fractures.

Introduction

Latissimus dorsi transfer is a procedure used in massive irreparable posterosuperior rotator cuff tears, in young patient with severe pain and significant functional impairment. The purpose of this retrospective study was to evaluate its clinical, radiological and electromyographic results.

Purpose of the study: The piriform syndrome is treated medically: functional rehabilitation and injections. If the medical treatment fails, tenotomy of the piriform muscle can be proposed. Published studies report good outcome in 66 to 87% Of patients. The purpose of this study was to examine the extrapelvic innervations of this muscle in order to assess the feasibility of neurotomy of he piriform muscle.

Material and method: Twenty gluteal regions were dissected. We studied first the relations between the piriform muscle and the ischiatic nerve. Then the innervations branches of the piriform muscle were localized in three landmarks.

Results: We found the of the six types of relation between the ischiatic nerve and the piriform muscle described by Beaton, with frequencies comparable to reports in the literature. Innervation of the piriform muscle does not follow a standard pattern, even though the innervations generally comes from the ischiatic nerve; the nerve branches come from the superior and inferior gluteal pedicles. In addition, these nerve branches penetrate the deep aspect of the muscle in random fashion. In addition, accessibility to the deep aspect of the piriform muscle cannot be achieved easily but requires prior section of its insertion on the greater trochanter.

Discussion: In our opinion, these results suggest that isolated neurotomy of the piriform muscle is not clinically feasible; it might be possible to improve function results of isolated tenotomy by performing a neurotomy of the nerve branches visible during the tenotomy procedure. A greater benefit might be expected in forms where the ischiatic nerve crosses the piriform muscle.

Purpose of the study: Little work has been done to assess outcome of rotator cuff tear repair in young adults aged less than 40 years. The purpose of our study was to assess the clinical and anatomic outcomes in a continuous series of arthroscopic rotator cuff repairs performed in patients aged less than 40 years.

Material and method: This was a retrospective analysis (2004–2007) of 15 young patients (age 18–39 years, mean 32.7 years) with rotator cuff tears confirmed on the arthroscan. All tears were repaired arthroscopically using the same reinsertion technique with anchors. Patients underwent bilateral assessment (SSV, Constant) at at least 12 months follow-up. A control imaging with injection (arthroscan or arthroMRI) was available in 12 of 15 patients.

Results: The series included 7 female and 8 male patients, 13 right and 2 left shoulders; 14 of 15 shoulders were on the dominant side. The time from symptom onset to surgery was 26 months on average. Patients were reviewed at mean 31 months follow-up. Preoperative range of motion was preserved in all patients. The mean preoperative Constant score was 55.5 on the operated side and 91.4 on the other side. The preoperative arthroscan demonstrated partial deep tears of the supraspinatus or infraspinatus in 5 patients with a posterosuperior impingement. The ten other shoulders exhibited full thickness tears of the supraspinatus. At last follow-up, the mean Constant score was 77.2 (range 44–90) with significant improvement of all partial scores except force. Patients resumed their former occupational activities at mean 8 months (range 1–36); resumption of sports activities occurred during the 7th month. Subjective satisfaction rate was 81.7%. Postoperative imaging with injection showed a healed cuff in 83% of the shoulders reviewed (10/12).

Discussion: Rotator cuff tears are exceptional in young subjects aged less than 40 years; there is considerable potential for worsening. Outcome after rotator cuff repair is very age dependent. It is important to diagnose these tears early to enable early repair; the anatomic results are good and persistent in younger patients.

Purpose of the study: Posterior glenoid erosio is a common finging in patients with degenerative joint disease of the shoulder. Anterior release is usually recommended, almost always with correction of the glenoid retroversion. There is no real consensus on the gravity of these posterior lesions nor on the appropriate attitude. The purpose of this study was to define the limitations of asymmetrical reaming during correction of excessive glenoid retroversion during total shoulder arthroplasty.

Material and methods: Five fresh cadaver shoulders were used. The size of the glenoid cavity and the humeral head were measured to select the optimal size for the glenoid implant. The scapula was embedded in resin. Posterior glenoid erosion was created by reaming to simulate wear producing retroversion greater than 15°. A control computed tomography (CT) was obtained to verify the lesion. The glenoid cavity was then prepared in the same manner as for prosthesis implantation, restoring neutral version to enable implantation of the prosthetic component of the size initially determined. A second CT was obtained to confirm the correction of the retroversion.

Results: The retroversion was corrected in all cases. At least one point of the implant penetrated the glenoid wall in all cases. In three cases, four points were outside the wall. In one case, reaming caused a fracture of the anterior glenoid rim. Finally, in one case, the size of the implant had to be reduced to avoid an oversized implant.

Discussion: The limitations for asymmetrical reaming to correct for posterior wear yet leave enough bone stock for implantation of a glenoid prosthesis are not defined. This study shows that asymmetrical reaming of the anterior rim of the glenoid cavity cannot satisfactorily correct for glenoid retroverson greater than 15° because of the frailness of the anterior wall and the risk the points will penetrate the rim. These complications compromise the primary stablity of the prosthesis and probably secondary short-term and mid-term stability.

Conclusion: If the glenoid retroversion is excessive (> 15°), it would be advisable to graft the posterior defect.

Purpose of the study: One of the most frequent complications of medial meniscal suture is injury to the saphenous nerve or its branches. The purpose of this study was to ascertain the relations of the medial meniscus with the infrapatellar branches of the saphenous nerve.

Material and methods: Twenty lower limbs were dissected to study the pathways of the saphenous nerve and its branches in relation to different landmarks of the medial meniscus and palpable bony zones. Sixteen measurements were made on each knee held in extension.

Results: The infrapatellar trunk of the saphenous nerve exhibited two terminal branches in all knees dissected. Level of the bifurcation in relation to the joint space varied. Similarly the position of the branches varied greatly in relation to different landmarks. The most frequent configuration was a main trunk situated 8 mm anteriorly to the tubercle of the great adductor and 60 mm from the mid point of the medial border of the patella. The bifurcation into two branches was situated 23 mm above the joint space. The two branches ran obliquely anteriorly and inferiorly forming an angle of 55° on average with a vertical line. The superior branch ran 24 mm behind the anterior meniscal point and 55 mm from the posterior meniscal point; the inferior branch ran 42.6 mm and 38 mm from these two points.

Discussion: Injury to the saphenous nerve or its branches is mainly observed for suturing techniques done medially to laterally. Incidence has reached 38% in certain series. This incidence has declined with the increasingly widespread use of arthroscopy, but saphenous injury still occurs for meniscal repairs using a posteromedial approach. The risk is similar for medially to laterally or laterally to medially sutures. Since there is no safety zone, it would be advisable to prefer an «all medially» technique.

Conclusion: Measurements made on dissection specimens enabled us to delimit three zones of increasing risk for nerve injury. The zone with the highest risk measures 20 mm wide. Its anterior limit is situated behind the most anterior meniscal point and its posterior limit is situated 28 mm from the posterior meniscal point.

Purpose of the study: First described in 1990, superior labral anteroposterior (SLAP) lesions are uncommon and remain a subject of debate. Initially treated by decridement and vivication, indications for reinsertion became increasingly population. The purpose of this study was to evaluate the long-term outcome of arthroscopic treatments.

Material and methods: Isolatd SLAP lesions were treated in 24 patients from 1996 to 2002. This study excluded all patients with rotator cuff tears, glenohumeral instability, a posterosuperior impingement, osteoarthritic degradation, or acromioclavicular pain. Thirteen patients (54.2%) reported that trauma was the triggering factor. Sixteen of the 24 patients practiced sports (seven leisure sports and nine competition sports included two at a high level). The diagnosis of SLAP lesion was suspected preoperative in 15 patients (62.5%) on the basis of clinical and arthroscan findings.

Results: The Snyder classification at arthroscopy was: type I (n=5, 21%), type II (n=17, 71%), type III (n=2, 8%). Debridement avivement was used for type I and III lesions. SLAP II lesions were treated by suture on one or two anchors. There were three complications: one anchor migration and two cases of reflex dystrophy. Twenty cases were reviewed with mean four year follow-up (minimum two years) (ten patients seen at consultation and ten with phone interviews). Only six patients recovered complete shoulder function. Among the ten patients examined, the Constant score improved 18.5 points. 65% of patients were satisfied or very satisfied.

Discussion: The results obtained in this series are in agreement with the literature. Repeated procedures performed in athletes or other professionals favor SLAP lesions. Diagnosis is difficult. Type II SLAP lesions predominate. We did not have any type IV lesions in this series. Adapted surgical treatment enables more or less complete resolution of the symptoms. Resumed physical activity at the same level cannot be guaranteed for the athlete.

Conclusion: SLAP lesions are a rare entity and are difficult to diagnose. Such lesions are a potential diagnosis in the event of posttraumatic painful shoulder or in patients exposed to repeated movements. Arthroscopic treatment is the rule, even though the outcome is uncertain.

Purpose of the study: This retrospective study was conducted to analyze the mid-term effect of damage to the anteroinferior rim of the glenoid cavity in failed arthroscopic stabilization of the shoulder.

Material and methods: From 1999 to 2001, 54 patients underwent surgery performed by the same operator. Full data were available for analysis for 46 patients. Mean age was 28 years and mean follow-up four years. A pre-operative scan was available for all patients to analyze the bone lesions. The same technique was used for all shoulders: three or four suture points using resorbable thread attached to a Panolok anchor with a north-south retension effect. The Duplay score was noted at last follow-up. Experimental work by Gerber, which demonstrated that the anti-dislocation resistance decreased as a function of the ratio (x) between the length of the anteroinferior glenoid defect and its maximal antero-posterior diameter, was used to assess resistance to dislocation. This resistance decreased 30% when x=0.5 and 50% when x=0.75.

Results: The Duplay score at 47 months was 83.3. The rate of recurrence was 13% (n=6). Age, sex, and number of episodes of instability had little effect on outcome. The rate of recurrence (38%) in patients with a significant damage (x> 0.5) was much higher than in patients with minimal damage (x< 0.5) (2.2%). The difference was statistically significant (p< 0.01). The Duplay score (63.8 points) in patients with significant damage (x> 0.5) was significantly lower (p=0.01) than in patients (91 points) with minimal damage (x< 0.05).

Discussion: The presence of bony lesions of the anterior glenoid rim appears to be one of the most important prognostic factors of recurrence. Considering the high frequency of these lesions in our series (54%), this element deserves careful analysis which would require computed tomographic reconstruction in the sagittal plane to obtain a precise assessment of the loss of articular surface. The statistical analysis demonstrated that patients with important loss of articular surface (x> 0.5) had a significantly higher risk of recurrent instability (p< 0.01).

Conclusion: Arthroscopic stabilization of the shoulder joint yields results similar to those obtained with more conventional techniques. Our study confirmed this notion showing a rate of recurrence of 13% which could be reduced to less than 3% with careful preoperative assessment of glenoid articular surface loss on the preoperative scan.

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: Removal of intra-articular foreign bodies (FB) constitues a major indication for elbow arthroscopy. The purpose of our study was to evalute our experience with arthroscopic treatment of elbow osteochondromatosis.

Material and methods: Between September 1988 and June 2001 we performed elbow arthroscopy in 25 active patients (15 manual workers, 8 athletes including 2 high-level) who presented intra-articular FB osteochon-dromatosis of the elbow. Male gender predominated (n=22). Mean age at intervention was 42 years (17–68). The right (n=21) and dominant (n=24) side predominated. The mean clinical course before arthroscopy was two years. Seven patients had had upper limb trauma (five with elbow injury) a mean 60 months (6–144) before arthroscopy. Clinical assessment before arthroscopy and at last follow-up (mean follow-up 60 months, 8–138) included pain score (visual analogue scale), the notion of blocking and joint effusion and joint motion, as well as index of functional impairment during occupational and recreational activities and a subjective satisfaction index. Standard x-rays and arthroscan were obtained before arthroscopy to identify and evaluate intra-articular foreign bodies. Cartilage damage and presence of synovial anomalies were evaluated on the preoperative scan and during the intervention. Arthros-copy was performed according to the same procedure in all cases: lateral decubitus, arm cuff, anterior expoloration (anteromedial and anterolateral access). Standard x-rays were also obtained after arthroscopy and at last follow-up.

Results: FB were found and extracted in all cases. Cartilage injury was associated in 14 cases. Synovectomy was performed systematically in case of synovitis, a macroscopic synovial anomaly, or to extract a FB trapped in the synovial (n=18). Osteophytes were shaved in 12 cases. The post-arthroscopic period was uneventful with no complications (vascular, nervous, infectious). Clinical improvement was significant and sustained and the occupational and recreational function indexes improved. The subjective satisfaction index remained high five years after arthroscopy. We did not have any clinical recurence (blockage) or radiographically detectable anomaly at last follow-up. Less favourable results (persistent pain) were obtained in patients who had cartilage injury.

Discussion: Arthroscopy appears to be a safe treatment with long-term efficacy for osteochondromatosis of the elbow. Long-term prognosis is influenced most by presence of cartilage injury.

Purpose: Suture anchors used for reinserting soft tissue on bony structures have been studied with the purpose of evaluating hold in bone. There has not however been any work on the influence of the eye design on suture resistance. The purpose of this work was to examine this aspect of the question.

Material and methods: The following anchors were tested: Statak 4 (Zimmer, Warsaw, IN, USA), Corkscrew 3.5, Fastak 2.4 (Arthrex, Naples, FL, USA), PeBA C 6.5 (OBL, Scottsdale, AZ, USA), Mitek GII 5Mitek, Norwood, MA, USA), Harpoon 2 (Arthrotek, Warsaw, IN? USA), Ultrafix (Linvatec, Largo, FL, USA), Vitis 3.5 AND 5 (Tornier, St Isnier, France). The following suture threads were used: Vicryl dec 5, Flexidene dec 5, PDS dec 4. Three types of tests were performed on an Instron 8500+. To study loading at thread rupture, a loop with a constant length was placed under traction in the axis of the anchor until thread rupture. Two measurement modalities were used. For the first, static tension was applied to increase the linear load at the rate of 1.25 mm/s. In the second, cyclic traction applied tension five times at a frequency of 1 Hz with 10N loading increments. To study thread weakening in relation to each anchor, we imposed a back and forth movement on the strand running through the eye using a sinusoidal 10 mm movement at a frequency of 0.03 Hz, one end of the thread being fixed and the other supporting a constant 20 N load. Each thread was tested in each anchor and each type of test was run three times.

Results: Load at rupture of each thread was not affected significantly by the design of the anchor eyes. Rupture generally occurred at the knot level, sometimes at the eye (Harpoon, Fastak, Vitis) for the Flexidene dec 5 thread. Conversely, there were important differences in the thread weakness tests: a knitted thread such as Vicryl was much stronger than the two other threads tested, irrespective of the anchor. Furthermore, resistance for the dynamic test was very variable for the different anchors: 100±20 cycles for corkscrew 3.5 and 3±1 cycles for Vitis 3.5 with Vicryl or 6+/1 cycles for Harpoon 2 with Flexidene.

Conclusion: The design and finishing of each eye had an effect on the resistance of thread moving through the eye. For anchors which weakened thread after a few back and forth movements, it can be assumed that simple knotting damages the thread to a point where early failure occurs at reinsertion. The best results were obtained when the anchor eye had a bevelled groove.

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.