Acetabular defect classification and surgical reconstruction in revision arthroplasty. A 6-year follow-up evaluation

From 1982 to 1988, 147 cemented acetabular components were revised with cementless hemispheric press-fit components, with an average follow-up period of 5.7 years (range, 3-9 years). Acetabular defects were typed from 1 to 3 and reconstructed with a bulk or support allograft. Type 1 defects had bone lysis around cement anchor sites and required particulate graft. Type 2A and B defects displayed progressive bone loss superiorly and required particulate graft, femoral head bulk graft, or cup superiorization. Type 2C defects required medial wall repair with wafer femoral head graft. Type 3A and B defects demonstrated progressive amounts of superior rim deficiencies and were treated with structural distal femur or proximal tibia allograft. Six of the 147 components (4.0%), all type 3B, were considered radiographically and clinically unstable, warranting revision. Three of the six were revised. Moderate lateral allograft resorption was noted on radiographs, but host-graft union was confirmed at revision. Size, orientation, and method of fixation of the allografts play an important role in the integrity of structural allografts, while adequate remaining host-bone must be present to ensure bone ingrowth.

Arthroscopic labral repair to the glenoid rim

The purpose of this study was to develop a new arthroscopic approach for traumatic instability that effectively reattaches avulsed capsulolabral tissue to the glenoid articular rim with sutures. This technique does not depend on fixation devices, trans-scapular drilling, or implantation of suture anchors. We attached a three-dimensional position sensor and force and torque transducer to the humerus and scapula of eight normal cadaveric shoulders to measure the normal, surgically unstable (arthroscopic Bankart lesion), and repaired preparations. We assessed eight motion ranges and six laxity tests. Capsulolabral release increased all passive ranges and allowed significant translational increases on posterior drawer and crank testing. After repair, motion was never decreased and there were no differences in laxity relative to normal. Neurovascular structures were never at risk. Our arthroscopic repair provides anatomic reattachment and effective deepening of the glenoid con-cavity similar to that achieved by open repair. This new method restores joint stability, preserves motion, and can withstand forceful loads. Ongoing clinical trials will substantiate whether the technique is as safe and reliable as shown cadaverically.

Osteonecrosis of the femoral head treated with total hip arthroplasty without cement

With use of porous-coated implants, total hip arthroplasty was performed in a consecutive series of thirty patients (thirty-five hips) who had a preoperative diagnosis of late-stage (Ficat and Arlet stage-III or IV) osteonecrosis of the femoral head. The patients were evaluated clinically and radiographically, and the data were recorded in a prospective manner. The average duration of follow-up was seven and one-half years (range, five to ten years). The average age of the patients at the time of the operation was thirty-two years (range, twenty-one to forty years). Signs of osseointegration of the femoral stem to the host bone were demonstrated in thirty-three hips (94 per cent). In the porous-coated hemispherical acetabular cups of these hips, an optimum bone-implant interface was identified and maintained, suggesting bone ingrowth. The rate of revision was 3 per cent (one hip) for the femoral side and 6 per cent (two hips) for the acetabular side, for an over-all rate of 6 per cent. All patients maintained a high level of activity postoperatively. There was moderate or severe remodeling of proximal femoral resorptive bone and stress-shielding in six hips (17 per cent) and osteolytic reactions in six hips. Complications were frequent (six hips) and included one deep infection; two dislocations; two instances of heterotopic ossification; and one fracture of the calcar femorale, which occurred intraoperatively. The thirty patients had a lower rate of revision and improved clinical outcomes compared with other reported series of young patients managed with total hip arthroplasty with cement who had the same diagnosis and similar postoperative follow-up. However, the latter series involved implants of an earlier design that had been inserted with older techniques of cementing. When arthroplasty is considered for the treatment of late-stage osteonecrosis of the femoral head in young patients, the use of total hip implants without cement that allow for bone ingrowth appears to be a viable alternative to arthroplasty with use of cement. However, longer follow-up is needed to determine the outcome of the osteolytic reactions that we observed. We therefore recommend this procedure with some caution because of the high rate of complications and the potential for failure of the arthroplasty related to the osteolytic reactions.

Review on tension in the natural and reconstructed anterior cruciate ligament

This article reviews the methodology and results of published studies concerned with tension in the natural and reconstructed anterior cruciate ligament (ACL). This also includes studies of fiber length changes with knee motion and the relationships between graft tunnel placements and isometricity. Little work has been done in vivo: in humans, length changes of the anterior ACL fibers have been measured at operation, while animal longitudinal studies have been few and have given conflicting results. Work in vitro has used many methods to study ACL tension directly or indirectly, via length changes in fibers, but many authors have reported variable results, caused partly by inter-specimen differences and lack of control of forces or kinematics. It seems likely that different grafts require different peroperative tensions to restore normal stability when measured immediately after application at one knee position. But graft placement and the angle at which tensioning is performed also matter. Over-tensioning constrains knees under load cycling. Similarly, it is difficult to measure and therefore also to decide how tension should be distributed between an ACL graft and and augmentation to the graft. It was concluded that the published studies provide many guidelines for the effects of different graft placements or tensioning protocols but, overall, there is little firm evidence on which to recommend any particular ACL reconstruction protocol.

Tibial attachment area of the anterior cruciate ligament in the extended knee position. Anatomy and cryosections in vitro complemented by magnetic resonance arthrography in vivo

Knowledge of the anatomy of the anterior cruciate ligament (ACL), including its course and orientation in relation to the roof of the intercondylar fossa, is a prerequisite for successful intra-articular ACL reconstruction. To attain precision placement of the tibial attachment site and to avoid graft/roof conflict in the extended knee position, we assessed the anteroposterior tibial insertion of the ACL in the midsagittal plane of the extended knee. We measured the anterior-posterior (AP) limits and the center of the tibial attachment area of the ACL from the anterior tibial margin. The inclination angle of the intercondylar fossa roof was measured with respect to the shaft axis of the femur. The tibial attachment area of the ACL was determined in ten cadaveric knees. Using the cryoplaning technique, we determined the tibial attachment of the ACL in five knees. Using contrast magnetic resonance arthrography (MRA), we measured the tibial insertion of the ACL in 35 patients (23 male and 12 female) with intact ACLs. The total AP midsagittal diameter of the tibia averaged 51.0 +/- 5.8 mm in the cadaveric knees, 49 mm on cryosections, and 53.7 mm in men and 49.0 mm in women with MRA. The average anterior limit of the ACL, measured from the anterior tibial margin, was 14 +/- 4.2 mm in the cadaveric knees, 12.1 mm at cryosectional anatomy, and 15.2 mm in men and 13.4 mm in women with MRA.(ABSTRACT TRUNCATED AT 250 WORDS)

Infraspinatus muscle-splitting incision in posterior shoulder surgery. An anatomic and electromyographic study

Standard posterior shoulder surgical approaches include infraspinatus tendon detachment and infraspinatus-teres minor interval development. Cadaveric and clinical investigation of a new infraspinatus-splitting approach to the posterior glenohumeral joint was undertaken to assess efficacy in providing exposure, preserving tendon attachment, and avoiding neurologic compromise. Infraspinatus musculotendinous and neural anatomy was examined in 20 cadavers. Four patients with posterior shoulder instability underwent posterior capsulorrhaphy through this infraspinatus-splitting approach, followed by electrodiagnostic testing. Infraspinatus muscle was bipennate in all specimens, the tendinous interval an average 14 mm inferior to the scapular spine at the glenoid rim. The infraspinatus-splitting interval bisected the posterior glenoid rim at its midpoint, whereas the infraspinatusteres minor interval crossed the glenoid rim's lower quarter. The suprascapular nerve provided sole innervation to the infraspinatus muscle in all specimens, entering the infraspinous fossa at the notch as a single trunk 22 mm medial to the glenoid rim. Minimum branching variability was observed. Electrodiagnostic testing showed no evidence of axonal damage or muscle denervation in either infraspinatus pennate bundle. Limiting infraspinatus-splitting dissection medially to 1.5 cm from the posterior glenoid rim prevents damage to any interval-crossing suprascapular nerve branches. Posterior shoulder surgery through a horizontal, longitudinal infraspinatus tendon-splitting approach provides excellent exposure of posterior capsule, labrum, and glenoid, without requiring tendon detachment or causing neurologic compromise.

The effect of thread length and location on extraction strengths of iliosacral lag screws

Although iliosacral lag screws are an established technique for fixation of sacroiliac joint dislocation and sacral fractures, there is a paucity of data on the relative strength of fixation of screws in the sacral ala and body. The purpose of this study was to quantify and compare the extraction strength of cancellous screws in the sacral ala and body. Twelve fresh frozen cadaveric human pelves (mean age 76) were used to test the extraction strength of three groups of 7.0 mm cannulated cancellous screws: long-threaded in the sacral body, short-threaded in the body and short-threaded in the ala. The mean extraction strengths were 925, 374 and 71 newtons (or 92, 37, and 7 kg) respectively. The differences between the three groups were highly significant (all P < 0.0025). These data strongly recommend that the goal in iliosacral lag screw fixation should be to insert a long-threaded screw into the sacral body, if safely feasible. Fixation in the ala is inferior and should be avoided in the elderly.

[Indications, technique and results of treatment of fractures of the base of the first metacarpal bone with movement stable osteosynthesis]

We report about the indication, technique and results of 27 fractures of the base of the metacarpus I. All those fractures were treated by open reduction and screw-/plate osteosynthesis according to the AOSIF-technique. Using these implants and the technique of open reduction with an additional autologous bone graft it offers the possibility to start active motion therapy immediately after operation. Perioperative complications can be bypassed with the use of external mini-fixateur as well as in those cases of open fractures with various types of damage patterns. Total active mobility (TAM) of the thumb joints showed in our series of 27 treated fractures an active total mobility of 80% or more in 25 patients. There where three patients with wound healing disturbances. No fracture healed delayed or resulted in non union, no patient showed signs of reflex dystrophy, yet in two cases insufficient joint reconstruction had to be noted. Neither our own short followed-up results or those few cases published so far allow us a final critical judgement of the best technique in treating the fractures of the base of metacarpus I.

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction: a new technique of intraarticular measurement and modified graft harvesting

The purpose of this study was to determine the incidence of bitunnel interference fixation and accurate femoral insertion site targeting using a modified technique of endoscopic anterior cruciate ligament (ACL) reconstruction. Thirty-four consecutive central-third bone-patellar tendon-bone autograft modified endoscopic ACL reconstructions were prospectively studied. A new technique was used intraoperatively to directly measure (a) intraarticular (graft) distance (IAD) and (b) patellar tendon graft length, thereby allowing calculation of optimal tibial tunnel length for each case. Accuracy of guide pin placement through this tibial tunnel into the proposed femoral insertion site was assessed, as was the ability to achieve interference fixation in both tunnels (minimum of 20 mm bone interference fixation within the tibial tunnel). A new technique for patellar tendon-bone harvesting and proximal graft fixation to address graft mismatch is described. The average IAD from tibial origin to femoral ACL insertion measured 26.3 +/- 3.0 mm (range 21-33). The average patellar tendon length (LP) was 48.4 +/- 6.0 mm (range 40-63). The average calculated tibial tunnel length (TT) necessary to achieve bitunnel fixation (TT > or = LP + 20 - IAD) was 42.1 +/- 5.3 mm (range 36-57). Establishment of the calculated tibial tunnel length was achieved in 25 cases (74%) (no graft-tunnel mismatch). Graft-tunnel mismatch, in which the tibial tunnel could not be established to the length calculated necessary to accommodate a minimum of 20 mm of bone graft, occurred in nine cases (26%). Graft-tunnel mismatch occurred more frequently in patients whose patellar lengths were > or = 50 mm (p < 0.005), but was not found to correlate specifically to IAD. Recession of the graft up into the femoral tunnel allowed accommodation of the mismatched graft (bitunnel interference screw fixation) in these nine cases, averaging 22.0 +/- 2.98 mm (range 16-29 mm) of available distal bone block fixation. Tibial tunnel fixation of > or = 20 mm was achieved in 30 patients (88%), 18 mm in two, 17 mm in one, and 16 mm in one. Measurement error resulted in inadequate distal graft accommodation in four patients in whom error averaged 3 mm. Targeting of the femoral insertion site guide pin was achieved without requiring any knee manipulation for all cases. Patellar tendon graft protrusion through the tibial tunnel and potentially suboptimal graft fixation poses a frequent problem during endoscopic ACL reconstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Anterior and anterior-inferior shoulder instability: Treatment by glenoid labrum reconstruction and a modified capsular shift procedure

An anterior glenoid labrum reconstruction in conjunction with a modified anterior-inferior capsular shift is described and was performed in 64 patients (69 shoulders) with traumatic anterior or anterior-inferior glenohumeral instability. Sixty-three operations were performed for recurrent dislocation and six for recurrent subluxation. The patients in this study were extremely active in sports, with the majority of Tegner ratings exceeding 7.0. Fifty-six patients with 61 operated shoulders were available for clinical follow-up at an average of 36 months (range 28 to 78 months). With rating scales from the American Shoulder and Elbow Surgeons, pain improved from an average of 3.1 to an average of 4.4, stability improved from 1.1 to 4.5, and function improved from 2.5 to 3.8. Postoperative average ranges of motion were 180° of forward elevation, 72° of external rotation with the arm at the side, 92° of external rotation with the arm at 90° of abduction, and 90° of internal rotation with the arm at 90° of abduction. Ninety-five percent of the patients were satisfied with the procedure. Five patients suffered a recurrent dislocation, four from significant trauma. One additional patient experienced an episode of subluxation early in the recovery period. According to the criteria of Rowe, 90% had excellent or good results.

Humeral head prosthetic arthroplasty: Surgically relevant geometric considerations

The relationship of the humeral head prosthesis to the humerus is a critical determinant of the result in glenohumeral arthroplasty. With canal-fitting humeral prostheses, the position of the component is largely dictated by the location of the reamed medullary canal. This study explores the geometric relationships of a surgically defined humeral reference, the "orthopedic axis." This is the axis of a cylindric reamer or press-fit prosthetic stem inserted to the appropriate depth for the humeral prosthesis. The orthopedic axis provides a reference for measuring surgically important geometric features of the normal humeral articular surface and comparing them with those available with humeral prosthetic components. In 10 cadaveric proximal humeri, we measured the following seven parameters in a radiologic projection of the humerus on the plane transverse to the orthopedic axis: the surgically-determined reamed diameter of the humeral canal, the diameter of curvature of the humeral head articular surface, the effective humeral neck length, the combined head and neck length, the subtended angle of the humeral joint surface, the anterior/posterior offset of the center of the humeral head, and the biceps-articular surface angle. We then determined the prosthetic geometry of a canal-fitting humeral component necessary to match the stem size, head diameter, head and neck length, and effective humeral neck length. To examine the effect of changing component version, we determined the maximal angle of anteversion and retroversion achievable by rotation of the component about the orthopedic axis without compromising the tuberosities. In the maximal possible anteversion or retroversion, the combined head and neck length changed by only 2 mm. Thus the effect of component version of a press-fit prosthesis on glenohumeral soft-tissue tension is small. The study suggests that the surgeon controls relatively few important variables in a canal-fitting humeral arthroplasty. Kinematics of the arthroplasty are controlled primarily by soft-tissue releases and the selection of the prosthetic head-neck length.

The biomechanics of interference screw fixation of patellar tendon anterior cruciate ligament grafts

Twenty-seven paired human cadaveric knee specimens were used to determine the effect of surgical technique and various interference screw parameters on the pullout strength of patellar tendon femoral bone blocks. The study compared the fixation strength of endoscopically inserted and conventional "rear-entry" screws of different diameters and lengths. In all tests the most frequent mode of failure was bone block pullout from the interference screw. There was no significant difference in fixation strength between 9-mm diameter screws inserted through a conventional rear-entry technique and 7-mm diameter screws inserted through an endoscopic technique. There was no significant effect of screw length on fixation strength. The pullout force for 20-mm long screws increased on average 120% when 7-mm diameter screws were compared with 5.5-mm diameter screws. There was no significant effect of increased screw core diameter on fixation strength. There was a weak positive correlation (r2 = 0.45) between screw insertion torque and pullout force. Our measured mean pullout force for the 7-mm endoscopically inserted screws of 362 +/- 198 N represents 20.1% of the failure load of the normal young adult anterior cruciate ligament. Our data indicate that properly inserted 7-mm diameter endoscopic interference screws can provide fixation strengths of patellar tendon anterior cruciate ligament grafts equivalent to those of conventional 9-mm diameter rear-entry, outside-in screws.

Glenohumeral Instability: Evaluation and Treatment

Glenohumeral instability encompasses a spectrum of disorders of varying degree, direction, and etiology. The keys to accurate diagnosis are a thorough history and physical examination. Plain radiographs are frequently negative, especially in subtle forms of instability. Computed tomography (CT), CT arthrography, magnetic resonance imaging, arthroscopy, and examination under anesthesia may occasionally yield important diagnostic information. Nonoperative treatment of shoulder instability consists of reduction of the joint (when necessary), followed by immobilization and rehabilitative exercises. The length and the value of immobilization remain controversial. Rehabilitative programs emphasize strengthening f the dynamic stabilizers of the shoulder, particularly the rotator cuff muscles. Both arthroscopic and open techniques can be used for operative stabilization of the glenohumeral joint. Results of these repairs are assessed not only in terms of recurrence rate, but also in terms of functional criteria, including return to athletics. Some standard repairs have declined in popularity, giving way to procedures that directly address the pathology of detached or excessively lax capsular ligaments without distorting surrounding anatomy. Capsular repairs also allow correction of multiple components of instability.

The role of arthroscopy in the assessment and treatment of tibial plateau fractures

This retrospective study compared arthroscopic treatment of certain tibial plateau fractures to traditional open techniques. From January 1989 through August 1992, 40 patients with tibial plateau fractures were evaluated. After reviewing the records and radiologic studies, 23 patients were included in the study based on fracture patterns. Using Hohl's revised classification system, patients with either local compression or split compression fractures were included. Twelve of these patients were treated with arthroscopic reduction and percutaneous fixation (ARPF; group A). The remaining 11 underwent open reduction and internal fixation (ORIF; group B). The results of the ARPF group were superior to those of the ORIF group. In the ARPF group, all reductions were anatomic and remained fixed at least 3 months postoperatively, whereas only six (55%) of the ORIF patients had anatomic reductions initially. Furthermore, one of these patients had further loss of reduction on follow-up radiographs. Iliac crest bone graft was used in two patients in group A and 10 in group B. The use of bone graft in the arthroscopically treated group had no effect on the final outcome. The average length of postoperative hospitalization for the ARPF patients with isolated tibial plateau fractures was 5.36 days compared with 10.27 days for patients who were treated with ORIF. Average time to full weight bearing was 8.95 weeks in the ARPF group and 12.30 weeks in the ORIF group. No patients in either group had medial collateral ligament repairs. No ARPF-treated patients experienced valgus laxity after treatment. One patient in the ORIF group had residual instability and another walked with a cane.(ABSTRACT TRUNCATED AT 250 WORDS)

Anterior cruciate ligament fascia lata allograft reconstruction: progressive histologic changes toward maturity

Biopsy samples were obtained arthroscopically from 21 patients who had undergone anterior cruciate ligament (ACL) reconstruction using rolled, freeze-dried fascia lata allograft in order to evaluate progressive histologic changes toward maturation. The study period was 3-20 months postoperation. The mean age (+/- SEM) was 31.9 +/- 10.3. Histomorphometry was used for quantitative evaluation. Arthroscopic examination showed fully synovialized allografts in all patients. Varying degrees of degenerative tissues were observed histologically. There was a significant, direct correlation between the percentage of polarized tissue and the maturity of the biopsy specimen (r = 0.9; p < 0.04). The mean area of polarization in the postrehabilitation period (10-20 months) was significantly higher (p < 0.01) than in the rehabilitation period (3-20 months). Overall, there was a progressive decrease in cellularity and vascularity as the allograft matured. Compared with the biopsy samples of normal ACLs, the allograft was still undergoing maturation 20 months postoperatively.

Precision oblique osteotomy for shortening of the ulna

The obstacles of prolonged healing time and technically demanding osteotomy and plate fixation in the performance of ulnar shortening osteotomies have been overcome by a precision system that includes a 45 degrees osteotomy and 2.7 mm interfragmentary lag screw. In 23 transverse osteotomies healing time averaged 21 weeks with one nonunion. In 17 precision oblique osteotomies healing time averaged a substantially shorter 11 weeks. Biomechanical data obtained from cadaveric testing comparing these two constructs demonstrated a structural stiffness that was clearly greater in torsion testing for the oblique osteotomy. No biomechanical difference was identified in the anteroposterior and lateral bending tests. The system permits the reliable performance of two parallel osteotomy cuts, allowing the removal of a precise amount of bone. The compression device and specialized plate permit easy coaptation of the osteotomy surfaces, which are locked into position by a precise 22 degrees interfragmentary lag screw. The surgical procedure is more quickly completed, and the frustration of this previously challenging procedure is now completely removed.

Arthroscopically assisted repair of acute Bankart lesion

Acute traumatic anterior shoulder dislocations are associated with high recurrence rates in young athletic individuals. Arthroscopically assisted stabilization of acute initial traumatic anterior dislocation was carried out in 11 young athletes. The average age was 20 years, with nine males and two females. The anterior acute Bankart lesion was surgically repaired using the technique described by Caspari/Morgan. There were no surgical complications. All patients were able to return to their sport without restriction. One patient had a transient episode of instability 8 months postoperatively associated with trauma, but no further sequelae. Using the Rowe scale there were nine excellent and two good results. Using repair of a Bankart lesion provides a stable shoulder with minimal loss of function and low recurrence rate. Early intervention should be considered in young, highly competitive athletes.

Failures after revision hip arthroplasties with threaded cups and structural bone allografts. Loosening of 13/18 cases after 1-4 years

Uncemented threaded, smooth cup acetabular components and structural deep-frozen bone allografts harvested from femoral heads during arthroplasties were used for reconstruction of the acetabulum in 18 revision hip arthroplasties. Autogenous bone grafts were also used in every case. The mean follow-up time was 2.5 (1-4) years. Loosening of the prosthetic component occurred in 13 cases. In 8 cases revision of the acetabular component has already been performed, and 5 cases remain to be reoperated. The use of uncemented, threaded cups in combination with reconstruction of bone defects with structural allografts cannot be recommended in acetabular revisions.

Bone-grafting for acetabular deficiency during primary and revision total hip arthroplasty. A radiographic and clinical analysis

The use of bone-graft to augment the deficient acetabulum in primary and revision total hip arthroplasty (THA) is controversial. To identify factors affecting cup loosening in patients who received a bone-graft during THA, two orthopaedic surgeons retrospectively examined sequential radiographs. The surgeons also obtained independent computer measurements of hip center and cup abduction migration from preoperative, initial, and latest postoperative radiographs. Variables studied included host factors, graft factors, and technique factors. All conclusions were based on Kaplan-Meier log-rank analysis to account for differing lengths of follow-up periods among the cases. The authors report a series of 74 consecutive cases with a minimum 24-month follow-up period (mean, 40 months). All grafts appeared to unite. The clinicians found 80% stable cups, 8% possibly loose cups, and 12% (n = 9) definitely loose cups. In retrospect, technical errors were seen in six loose cups. Five revisions for loosening (6.7% of cases) were performed. Computer measurement found cup loosening in a higher percentage of cases than detected by the clinicians and did so an average of 18 months sooner. Acetabular cup loosening was associated with the American Academy of Orthopaedic Surgeons type III defects, use of allograft versus autograft, and initial cup abduction of 50 degrees or more. Kaplan-Meier survivorship analysis found 31% of cups radiographically loose and 15% revised at 5 years or more since surgery. Acetabular bone-grafting is technically demanding and should be employed when alternative reconstructions will not give a durable result.

Two-year follow up of bipolar hemiarthroplasty

Forty-seven bipolar hemiarthroplasties were performed from January 1985 to December 1986. Twenty-three patients (24 hips) returned for a history, physical, and repeat radiographs. Ten primary press-fit and two cemented primary bipolar hemiarthroplasties were performed. Four patients underwent cemented and eight received press-fit revision bipolar hemiarthroplasties. Fourteen patients had simultaneous cancellous, reamed femoral head autograft, or allograft acetabular bone augmentation. Omitting one patient who had replacement for Lévi's pleonosteosis, the average acetabular migration among the remaining 23 patients was 4 mm of superior and 1.5 mm of medial progression. The mean modified d'Aubigne hip score was 33 for primary press-fit arthroplasty, 30 for primary cemented arthroplasty, 22 for press-fit revisions, and 32 for cemented bipolar revision arthroplasty. Morcellized bone graft tended to variably resorb with time. Among the press-fit stems, all but two patients complained of at least occasional thigh pain. All but one patient with primary press-fit hemiarthroplasty walked with a limp. We conclude that, although good early results can be obtained, significant number of patients will have groin and thigh pain. We have found no evidence either radiologically or clinically that nonstructural bone grafting with reamed femoral head will reliably incorporate or prevent further acetabular migration.

Anterior shoulder instability in weight lifters

Occult instability is recognized as a major cause of shoulder dysfunction in throwing athletes. Few studies have characterized the findings of occult instability in nonthrowers. The purpose of this study was to examine shoulder instability in a group of weight lifters. The symptoms, physical findings, and results of treatment for 23 shoulders in 20 athletes are presented. All athletes presented with a complaint of progressive inability to perform exercises with the upper extremity in the abducted, externally rotated position (the "at-risk" position) because of pain. One hundred percent of the athletes experienced posterior shoulder pain when the shoulder was placed in forced abduction and external rotation. Thirteen shoulders in 10 patients responded to conservative management including aggressive rehabilitation and modification of technique to avoid the at-risk position. The other 10 shoulders, which did not respond to conservative treatment, required surgical treatment to alleviate the symptoms. All 20 patients have successfully returned to their previous weight lifting activities.

Biologic anchorage of cruciate ligament prosthesis. Bone ingrowth and fixation of the Gore-Tex ligament in sheep

The biologic fixation and strength of fixation of the polytetrafluoroethylene (PTFE) Gore-Tex ligament prosthesis was investigated in sheep knees. The device was inserted to replace the anterior cruciate ligament according to the recommended technique. Histological bone tunnel evaluation together with mechanical tensile studies were done at 6, 12, and 18 months. Already at 6 months the pull-out load of the prosthesis exceeded that of the normal ligament, and this finding persisted up to 18 months postoperatively. At 6 months there was marked fibrous tissue ingrowth into the prosthesis, and at 12 months trabecular bone had replaced the fibrous tissue between the interstices of the filaments; at 18 months bone even penetrated into the individual porous fibers of the prosthesis. The intra-articular part of the prosthesis was surrounded and partly invaded by undifferentiated connective tissue, with no recognizable macrophages or other inflammatory cells. In this experiment, the biocompatibility and porosity of the Gore-Tex prosthesis seemed optimal to permit ingrowth from surrounding fibrous and osseous tissues and firm anchorage into the bone tunnels.

Arthroscopic Bankart suture repair

The purpose of this paper was to report our experience with an arthroscopic technique of repair for the Bankart lesion following shoulder instability. Twenty-seven patients (average age, 21.7 years) were followed for an average of 36 months after arthroscopic suture stabilization of anterior shoulder instability. Patients were excluded if instability was multidirectional or voluntary and if there was radiographic evidence of a significant loss of glenoid bone stock. Clinical evaluation using a functional grading system showed that 10 patients were rated as excellent, 5 good, and 12 poor. Fourteen patients returned to their previous level of activity. There were 12 patients rated as failed; all had recurrent instability of the shoulder. Success was associated with a period of immobilization of 3 weeks or longer and a history of acute injury, especially subluxation. Failures were associated with shorter immobilization periods after surgery and in patients who had recurrent dislocations. The younger patient, who may not have complied with the immobilization protocol, also seemed to be associated with failure. Contact sports seems to leave a patient at high risk for recurrence. We recommend caution in the use of arthroscopic procedures for the competitive athlete in whom a second surgery and rehabilitation might mean loss of more sports participation.

Arthroscopic repair of superior glenoid labral detachment (the SLAP lesion)

Complete detachment of the glenoid labrum from the superior pole of the glenoid, which is associated with a destabilization of the origin of the long biceps tendon, leads to altered function in the shoulder joint. This is especially noticeable when the shoulder is used in overhead activities. Two operative techniques are described for reattachment of the glenoid labrum to the glenoid. In the first six patients the glenoid labrum was reattached with small cannulated titanium screws. In five patients these screws were inserted under arthroscopic control from a cranial direction. The labrum was always reattached just behind the origin of the long biceps tendon. The most favorable portal was identified by percutaneous probing with a Kirschner wire. If the superior glenoid pole could not be reached via a portal placed anterior or medial to the acromion, a hole was drilled through the acromion, and a transacromial approach was used. The screws were removed by arthroscopy after 3 to 5 months. In the last eight patients, absorbable tacks were used instead of screws. Of 18 patients who showed a complete detachment of the glenoid labrum from the superior pole of the glenoid with destabilization of the attachment of the biceps tendon, 14 underwent reattachment as described previously. The minimum follow-up time was greater than 6 months (mean follow-up time 18 months, maximum follow-up time 30 months). At follow-up, eight patients felt completely rehabilitated and had resumed their previous overhead activities (overhead sports). Four patients believed their conditions were improved. Two patients had not experienced any improvement. Of the patients who had not undergone reattachment and who had undergone shaving of the free margin of the glenoid labrum, only one had experienced improvement, while the other three patients did not report any improvement.

Total hip replacement without cement for non-inflammatory osteoarthrosis in patients who are less than forty-five years old

Forty-two patients (forty-four hips) who, at an age of less than forty-five years, had a total hip replacement without cement for the treatment of non-inflammatory osteoarthrosis, were followed for three to seven years (average, four and one-half years). At the latest follow-up evaluation, thirty-seven hips (84 per cent) had an excellent Harris rating; three (7 per cent), good; one (2 per cent), fair; and three (7 per cent), poor. The mean Harris hip score was 92 points, compared with 43 points before the operation. Two hips (5 per cent) had a revision due to complications. In another hip, there was a progressive radiolucent line around the femoral component, increased shedding of beads, and a low score for fixation and stability, according to the criteria of Engh et al. We concluded that total hip arthroplasty without cement, at least for the time-period studied, has a high rate of success for the management of patients less than forty-five years old who have non-inflammatory osteoarthrosis of the hip.

Thermal behaviour of hydroxyapatite intended for medical applications

Four commercial hydroxyapatites (both natural and synthetic) were tested to assess transformations of the chemical and crystalline structure following variation of temperature from 20 to 1600 degrees C. The thermal behaviour of hydroxyapatite is relevant for biomedical applications such as plasma spraying of metallic implants. Thermogravimetric analysis showed a weight loss from each hydroxyapatite specimen, due to a release of structural H2O molecules; all the specimens up to 1300 degrees C were made of crystalline hydroxyapatite, determined by X-ray diffraction; at 1470 degrees C they were made of both hydroxyapatite and calcium phosphate, but at 1570 degrees C of calcium phosphate exclusively. The diffractograms of the hydroxyapatite coatings showed the same peaks as the original powders, so at the chosen plasma-spray procedure level no new phases were formed. The peak height was nevertheless lower in the plasma-sprayed hydroxyapatites for all interplanar spacing values, which indicated a lower degree of crystallinity, associated with a random structure derived from an alteration to the original crystalline network.

Miniarthrotomy versus arthroscopic-assisted anterior cruciate ligament reconstruction with autogenous patellar tendon graft

The purpose of this study was to determine whether two groups of patients showed any early (6 months postoperative) clinical differences when treated by arthroscopic-assisted or miniarthrotomy anterior cruciate ligament (ACL) reconstruction. Fifty-two consecutive arthroscopic-assisted ACL reconstructions (Group I) were matched with 52 miniarthrotomy ACL reconstructions (Group II). An autogenous midthird patellar tendon was used in all reconstruction procedures. Group I patients were operated on by one surgeon (A.C.R.) and all Group II patients by another (K.D.S.). Both groups were similar with regard to age, sex, injury, chronicity, and previous knee surgical procedures. All patients were treated according to the same postoperative rehabilitative protocol (emphasizing early motion, immediate full passive extension, early functional activity) and evaluated on follow-up by the same personnel and protocol. Data collection included injury and surgery dates; total surgery and tourniquet times; length of hospital stay; drain output; inpatient pain medications used; follow-up range of motion at 1.5, 2.5, and 6 weeks postoperative; KT-1000 arthrometer measurements at 10, 16, and 26 weeks; and isokinetic measurements at 10 and 16 weeks postoperative. Results indicated that follow-up range of motion and KT-1000 measurements showed no statistical difference between groups. Isokinetic average scores for quadriceps strength at 180 degrees/s showed no differences at 10 and 16 weeks. The study suggested that ACL reconstruction with midthird patellar tendon performed by skilled surgeons using either open or arthroscopic-assisted techniques combined with an aggressive postoperative rehabilitation protocol will yield similar acceptable early clinical results.

Accurate preparation of the patella during total knee arthroplasty

The development of a resection guide that facilitates accurate preparation of the patella during total knee arthroplasty is reported. Use of the guide prevents tilting of the prosthesis, as well as over or underresection of the patella.

Proximal tibial osteotomy. A critical long-term study of eighty-seven cases

Eighty-seven valgus osteotomies of the tibia were performed in seventy-three patients for osteoarthrosis of the medial compartment of the knee; the median follow-up was ten years (range, three to fourteen years). The data were subjected to univariate and multivariate statistical analysis and to survivorship analysis. For these calculations, the end-point of failure was defined as an arthroplasty of the knee, and additional calculations were performed with the end-point defined as the performance of an arthroplasty or moderate or severe pain in patients who had declined an arthroplasty. None of the many risk factors that were evaluated could be found to be associated with the duration of survival, except for relative weight and angular correction. The median loss of correction after the osteotomy was 1 degree. If, at one year after the operation, the valgus angulation was 8 degrees or more, or if the patient's weight was 1.32 times the ideal weight or less, the probability of survival five years thereafter was at least 90 per cent and the probability ten years thereafter was at least 65 per cent. However, when valgus angulation at one year was less than 8 degrees in a patient whose weight was more than 1.32 times the ideal weight, the rate of survival decreased to 38 per cent five years thereafter and to 19 per cent ten years thereafter. There is a considerable risk of failure of a proximal tibial osteotomy if the alignment is not overcorrected to at least 8 degrees of valgus angulation and if the patient is substantially overweight.

The anterior labroligamentous periosteal sleeve avulsion lesion: a cause of anterior instability of the shoulder

Recurrent anterior unidirectional instability of the shoulder is not always associated with a classic Bankart lesion, which is an avulsion of the anterior labroligamentous structures from the anterior glenoid rim. Because the anterior scapular periosteum ruptures, the labrum and the attached ligaments are found to float out anterior to the glenoid rim when viewed arthroscopically. The anterior labroligamentous periosteal sleeve avulsion (ALPSA) of the supporting anterior inferior ligamentous and labral structures of the shoulder joint was found in four of eight acute primary anterior shoulder dislocations. This lesion differs from the Bankart lesion because the anterior scapular periosteum does not rupture, thereby allowing the labroligamentous structures to displace medially and rotate inferiorly on the scapular neck. These lesions eventually heal, and lead to recurrent anterior dislocations because of the subsequent incompetence of the anterior inferior glenohumeral ligament. An arthroscopic technique that converts the ALPSA lesion to a Bankart lesion and subsequently reconstructs the supporting anterior inferior structures of the shoulder has been successful in 26 cases (4 acute and 22 chronic) which were followed for > or = 2 years. Only one dislocation occurred, and it was the result of severe trauma.

A prospective study of 100 consecutive Harris-Galante porous total hip arthroplasties. 2-5-year results

This is a prospective study of the authors' first 100 Harris-Galante porous total hip arthroplasties (THA) that were followed for 2-5 years. The mean age of the 83 patients was 43 years. Using the Harris hip rating system, 80% of the hips were rated as excellent, 13% as good, 5% as fair, and 2% as poor at final evaluation. Eighty percent of the hips had no pain, 11% had slight or occasional pain, 8% had activity-related pain, and 1% had moderate pain. Eighty-seven percent of the hips had no limp, 8% had a slight limp, and 5% had a moderate limp. One femoral component, placed as a conversion of a loose bipolar hemiarthroplasty, has been removed for loosening. Two other hips have been reoperated, one for lengthening the femoral neck and one for changing the acetabular liner. There were no problems with acetabular screw fixation and no component migrated. Only two hips had 1 mm nonprogressive radiolucent lines in all three zones. Femoral component subsidence of 3 or more mm was measured in 16 hips, but was progressive in only 1. Radiolucent and radiodense lines were frequently seen in the nonporous coated regions of the femoral stem. Loss of proximal medial femoral bone density was seen in 59% of hips, and calcar resorption was seen in 16% of hips. Although the clinical results of this uncemented implant system were good or excellent in 93% of hips, the high incidence of femoral component subsidence is worrisome.

Removal of well-fixed cementless metal-backed patellar components

Removal of well-fixed, cementless metal-backed patellar components can be difficult due to lack of easy surgical access to the anchoring pegs. Five cases of total knee arthroplasty with failed metal-backed cementless patellar components with ingrown anchoring pegs are presented. A technique of removal of these components is described that preserves remaining patellar bone and provides easy access to the well-ingrown anchoring pegs, lessening the risk of fracture during patellar component extraction.

The subscapularis muscle and its glenohumeral ligament-like bands. A histomorphologic study

The subscapularis muscle and the distribution of its tendinous bands is of significance in the surgical management of the shoulder joint. This distribution pattern has not been previously described in detail. We feel that, in any anterior approach to the glenohumeral joint for fracture fixation, joint replacement, and soft tissue reconstruction, a thorough understanding of the distribution pattern of the subscapularis bands is essential. We examined the subscapularis muscles from five cadavers. Four sections from the lateral one-half of each muscle were custom-mounted and stained with Masson's trichrome. We found a consistent pattern in which the tendinous bands were evenly interspersed in the midportion of the muscle and condensed laterally into a single large, flat tendon in the superior two-thirds of the muscle. The inferior one-third remained muscular. Understanding this pattern should help the surgeon have confidence that he/she has obtained a more secure repair in procedures involving the subscapularis muscle.