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.

Synovitis and artificial ligaments

Sixty anterior cruciate Dacron prosthetic ligaments were placed arthroscopically in 57 patients from 1983 to 1985. Fifty-five of the 57 patients were followed for an average of 4.4 years. The complication rate at 13 months was 29%; at 4.4 years, 43%. There were 34 reoperations. In 16 knees (28%) the prosthesis had to be removed due to abrasion and arthritis with rupture of the prosthesis. Thirteen knees had chronic synovitis and one knee had bacterial infection, all of which were managed with arthroscopic debridement. Four knees required removal of the extraarticular staple. Clinical testing in 42 knees with the Dacron prosthesis still in place showed the Lysholm score improved from a preoperative score of 43 points to a score of 82 points after 5 years. Of the knees, 58% had a pivot shift of 2(+)-3+: a trace pivot shift in 30%; a negative pivot shift in only 12%. The KT-1000 arthrometer verified those pivot shifts. The results of this study are discouraging. The procedure was complicated by a high reoperation rate, usually secondary to arthritis. The impression was that although stability of the knee was improved by use of an artificial anterior cruciate ligament, the end result of the therapeutic procedure was the development of an iatrogenic model of degenerative arthritis in the human knee.

Suspensory apparatus prosthesis in the horse. Part 1: In vitro mechanical properties

Mechanical properties of equine suspensory apparatus preparations and three braided synthetic prostheses were evaluated in vitro. Force versus displacement plots and failure modes were recorded from single load-to-failure testing in 18 cadaver limbs before and after replacement of each suspensory apparatus with a prosthesis. Mean load at failure, energy to failure, and stiffness values of polytetrafluoroethylene (PTFE) prostheses were lower than those of the suspensory apparatus and aramid prosthesis. The PTFE prosthesis failed by elongation or rupture of the prosthesis. Mechanical properties of the aramid prosthesis with collar augmentation were not significantly different from the suspensory apparatus. The main site of failure in both aramid prostheses was at the screw fixation to bone.

The results of fresh-frozen patellar tendon allografts for chronic anterior cruciate ligament deficiency of the knee

This prospective study was done to evaluate the clinical outcome of fresh-frozen patellar bone-tendon-bone allograft tissue used as a substitute for chronic insufficiency of the anterior cruciate ligament. Forty-one patients were followed at a mean of 27 months after surgery. The mean time from injury to reconstruction was 34 months. The same operative procedure and postoperative rehabilitation was performed on each patient. The evaluation method consisted of subjective, objective, and instrumented laxity testing. Thirty-seven patients (90%) thought their knee was normal or improved after surgery and had no further episodes of giving way. The combined modified Hughston Knee Score revealed 30 patients (73%) with an excellent or good result and 9 patients (22%) with a fair or poor result. The mean postoperative Lysholm Knee Score was 91 (range, 56 to 100). Thirty-two had a negative pivot shift (78%). The postoperative KT-1000 arthrometer revealed 37 patients had an injured-to-uninjured difference of 5 mm or less (mean, 1.32 mm; range, 0 to 5). There were three traumatic failures at 24 months postoperatively in this group. There was no rejection phenomenon noted postoperatively. In addition, clinical observation showed less postoperative morbidity when compared to a matched autogenous patellar tendon control group.

Multidirectional shoulder instability. Clinical results of inferior capsular shift in an active-duty population

We reviewed the results of a capsular shift procedure performed on 10 active-duty patients with an average of 28 months follow-up. Improvement in pain, function, and stability occurred postoperatively in nearly all patients. Loss of total elevation and external rotation were minimal and an average of three spinal segments of internal rotation were lost. Only one patient required further surgery for recurrent instability and all patients except two reported over-all improvement. Dominant shoulders made greater improvements in pain, stability, and functional capacity than nondominant shoulders. Patients with generalized ligamentous laxity had less pain and more posterior instability than those without laxity. A history of an acute traumatic event was predictive of greater improvement in pain and stability. A previous instability repair was indicative of the most postoperative instability and least functional improvement.

Clinical and radiographic analysis of the uncemented LSF total hip arthroplasty

Forty-nine consecutive uncemented porous-coated LSF total hip prostheses were implanted in 41 patients and studied prospectively. Clinical rating as described by Harris was performed preoperatively, at 6 months and 1 year postoperatively, and annually thereafter. Anteroposterior and lateral radiographs were obtained preoperatively, immediately postoperatively, at 6 and 12 months, and annually thereafter. At the most recent follow-up visit, patients were evaluated clinically and radiographically utilizing the format recently recommended by the Hip Society. A patient satisfaction questionnaire was also completed. The follow-up period averaged 37 months (range, 24-48 months). Preoperative hip scores averaged 38 (range, 18-68) and improved to 93 at the most recent follow-up visit (range, 76-100). The incidence of mild pain was 14% at 1 year and 4% at 2 years or more. The incidence of limp was 16% slight and 8% moderate at 1 year, and 12% slight and 2% moderate at 2 years or more. Surgical fit was objectively graded as excellent in 61%, good in 33%, and poor in 6%. The authors were unable to correlate surgical fit with clinical scores or radiographic findings. According to radiographic criteria, all components were judged to be stable and 86% were judged to demonstrate objective signs of osseointegration. Patient satisfaction with the procedure was 100%. All patients stated that the procedure increased their function and decreased their pain and need for medication. Compared to a normal hip, in terms of symptoms and function, the patients rated their postoperative hip at 85% (range, 50-100%). Compared to their level of activity before their hip was symptomatic, they rated their current activity level as 83% (range, 50-100%).