The relationship between anterior cruciate ligament reconstruction tibial tunnel location and the anterior aspect of the posterior cruciate ligament insertion

A retrospective study of arthroscopic anterior cruciate ligament reconstruction in 20 patients was conducted. These patients underwent computed tomography (CT) scans on the involved knee postoperatively to determine sagittal placement of the proximal end of the tibial tunnel (TTp) based on a distance from a specific anatomic reference known as the over-the-back (OTB) ridge. The distance from the posterior aspect of the TTp to the OTB ridge, defined as the backset, was measured from the CT scans. The mean backset was 6.2 mm. The anterior to posterior (AP) tibial plateau diameter was measured from the CT and by plain view radiograph. The mean AP diameter by CT scan was 55.1 mm and the mean AP diameter by radiograph was 55.4 mm. A Pearson correlation coefficient of r = .633 comparing backset versus AP diameter suggests a moderately significant positive relationship. For the AP diameter comparing measurement method, CT versus radiograph, r = .985, representing a highly significant positive relationship, confirming AP diameter sizing accuracy by inexpensive radiography versus CT scan. A proposed backset model based on these data uses three fixed distances, derived by ratio, within a 2-mm range. This model is defined by 5-, 6-, and 7-mm backset intervals for < 50 mm, 50 to 60 mm, and > 60 mm AP diameters respectively, and is currently under prospective clinical investigation.

Resurfacing of the patella in total knee arthroplasty. A prospective, randomized, double-blind study

During a two-year period, eighty-nine patients who were scheduled to have a total knee arthroplasty for the treatment of degenerative osteoarthrosis were randomly assigned to one of two groups: resurfacing of the patella or retention of the patella. All patients received the same posterior cruciate-sparing prosthesis, and all operations were performed by, or under the direct supervision of, one of us. Three patients died in the early postoperative period. The remaining eighty-six patients (118 knees; fifty-eight that had had resurfacing of the patella and sixty that had not) formed the study group. They were followed for a mean of thirty months (range, twenty-four to forty-four months). Evaluation was performed with use of the clinical scoring system of The Knee Society, a patient-satisfaction questionnaire, specific questions regarding patellofemoral symptoms and function, and radiographs. All clinical evaluations were performed by the same research nurse, without the involvement of a physician, in a blinded manner (neither the nurse nor the patient had knowledge of whether the patella had been resurfaced). Preoperatively, the mean Knee Society score, on a scale ranging from 0 to 200 points, was 89.7 points (range, 33 to 132 points); postoperatively, this score improved to a mean of 172.7 points (range, 98 to 200 points). With the numbers available for study, we could detect no significant difference between the knees that had had patellar resurfacing and those that had not with regard to the over-all score (p = 0.63), the subscore for pain (p = 0.56), or the subscore for function (p = 0.77). We also could detect no difference between the treatment groups, with the numbers available, with regard to patient satisfaction or the responses to questions involving the function of the patellofemoral joint, including the ability to exit from an automobile, to rise from a chair, and to climb stairs. Thirty-two patients had bilateral total knee replacement with resurfacing of the patella in one knee and retention of the patella in the other. These patients expressed no clear preference for either knee. Eight (13 per cent) of the sixty knees that had not had resurfacing were painful anteriorly compared with four (7 per cent) of the fifty-eight that had; this was not a significant difference (p = 0.38), with the numbers available. The anterior pain that was noted postoperatively was predominantly of new onset; it had not been observed preoperatively in three of the four knees that had had resurfacing or in four of the eight that had not. No additional treatment options were offered to the patients who had anterior pain in the knee after resurfacing. However, six (10 per cent) of the sixty knees that had not had resurfacing had it subsequently, because of anterior pain in the knee, after the twelfth postoperative month (range, fifteen to thirty-nine months). The pain decreased in four of these knees. Thus, total knee arthroplasty with retention of the patella yielded clinical results that were comparable with those after total knee arthroplasty with patellar resurfacing, but it was associated with a 10 per cent prevalence of the need for subsequent resurfacing. The prevalence of anterior pain after total knee arthroplasty was not influenced by whether or not the patella had been resurfaced. The postoperative clinical scores, the postoperative development of anterior pain, and the need for subsequent resurfacing were not predicted by the presence of preoperative anterior pain, obesity, or the grade of chondromalacia observed intraoperatively. Because of the short duration of follow-up, these results should be considered preliminary. Additional follow-up is planned.

The use of the Ilizarov technique in the correction of lower extremity deformities in children

The first time the Ilizarov technique was used at Children's Hospital of Los Angeles, 25 limb segments were treated in 15 patients. Thirteen segments (52%) required angular correction, 6 (24%) required lengthening, and 6 (24%) required both angular correction and lengthening. Average angular correction was 21 degrees (8 degrees to 41 degrees); average length gained was 44 mm (25 to 85 mm). All patients except two achieved preoperative goals. A total of 17 minor (.68/limb) and four major (.16/limb) complications occurred in the 25 limb segments in the study. The total complication rate was .84 complications per limb segment. The most common complication was pin tract infection (11 patients). This comprised 52% of complications and occurred in 44% of limb segments.

A rigorous comparison between the sexes of results and complications after anterior cruciate ligament reconstruction

Although there is a higher relative incidence of anterior cruciate ligament injuries in female than in comparable male athletes according to the literature, the majority of populations studied after reconstruction are male-dominated. We wished to determine whether a selection bias for reconstruction based on sex is warranted according to complications and outcome. Ninety-four patients (47 of each sex) were matched for chronicity of injury, age, preoperative sports activity levels, articular cartilage condition, and months of followup. All had patellar tendon autogenous reconstruction and a similar program of immediate knee motion and early return to function. The results were rated with the Cincinnati Knee Rating System. At a mean of 26 months postoperatively, there were no significant differences for complications or outcome between men and women. Women required an average of six more rehabilitation visits than men; however, none required additional surgery for knee motion complications and the rate of patellofemoral crepitus conversion was only 7%, lower than that found for men (15%). The overall failure rate was low, only 6% for women and 4% for men. We concluded that the functional rehabilitation program was effective, postoperative complications were few, and no scientific basis exists to use sex alone as a selection criteria for anterior cruciate ligament reconstruction.

A comparison of results in acute and chronic anterior cruciate ligament ruptures of arthroscopically assisted autogenous patellar tendon reconstruction

We conducted a prospective study of 94 consecutive patients who received a patellar tendon autograft for anterior cruciate ligament rupture. Eighty-seven patients (93%) returned for followup a mean of 28 months postoperatively; 57 had chronic and 30 had acute or subacute ruptures. There were no significant differences between the subgroups for age, sex, articular cartilage lesions, or months of followup. Forty-six meniscal tears were repaired; 27 of these extended into the central avascular region. Rehabilitation emphasized immediate knee motion, but strenuous activity was delayed for at least 4 months. Only one patient had a knee motion complication, and stability (<3 mm, KT-2000 arthrometer, 134 N) was restored in 85% of knees with chronic ruptures and 92% of knees with acute ruptures. Earlier reconstruction should be considered in active persons as symptoms and limitations continued postoperatively in knees with chronic ruptures, leading to overall less satisfactory results. In patient rating of the overall knee condition, 69% of knees with chronic ruptures and 100% of knees with acute ruptures scored in the normal or very good range. Repair of meniscal tears that extend into the central avascular region should be considered, as 24 of the 27 (89%) menisci repaired showed clinical evidence of healing and did not require reoperation.

Long-term clinical consequences of stress-shielding after total hip arthroplasty without cement

Remodeling of the femur, or so-called stress-shielding, was observed on the two-year postoperative radiographs of forty-eight (23 per cent) of 207 hips that were part of a consecutive, non-selected series of 223 hips that had had a primary arthroplasty with use of the anatomic medullary locking hip system. Three patients (three hips) died within ten years after the arthroplasty, leaving forty-four patients (forty-five hips) who had a minimum of ten years of clinical follow-up. At the time of the latest follow-up, thirty-eight patients (86 per cent) reported that they had either no or mild pain related to the hip, forty-two (95 per cent) had less pain than they had had preoperatively, and forty-one (93 per cent) were satisfied with the results of the arthroplasty. Two patients had a reoperation, but neither procedure involved the femoral component; specifically, one patient had a revision of a loose acetabular component and one had an exchange of a polyethylene liner. No femoral component was associated with clinical or radiographic evidence of loosening. Femoral osteolysis, confined to zones 1 and 7 of Gruen et al., was observed on the ten-year radiographs of four of the thirty-three hips for which such radiographs were available. Stress-shielding (defined as evidence of pronounced femoral bone-remodeling on the two-year radiographs) had not adversely affected the outcome for these four hips by the time of the latest follow-up. The findings regarding postoperative pain, function, and over-all satisfaction for the forty-four patients (forty-five hips) who were included in the present study were similar to those reported for our larger (parent) series of patients who had been managed with the anatomic medullary locking hip system and to those reported for a similar series of patients who were followed for 9.5 years after the insertion of a porous-coated anatomic prosthesis. In addition, the prevalence of acetabular and femoral osteolysis (four [12 per cent] of thirty-three hips) and that of revision of the femoral component (zero [0 per cent] of forty-five hips) were lower than those for our larger (parent) series (fifty-four [39 per cent] of 137 hips and three [1 per cent] of 201 hips, respectively) as well as those for the series of patients who had been managed with the porous-coated anatomic prosthesis (thirty-five [45 per cent] and four [5 per cent] of seventy-eight hips, respectively).

Pseudoaneurysm of the superior gluteal arterial system: an unusual cause of pain after a pelvic fracture

This case report describes a complication after treatment of a rotationally unstable pelvic fracture: a pseudoaneurysm of the superior gluteal arterial system. The patient sustained an anterior-posterior compression pelvic fracture that was stabilized with anterior symphyseal plating and percutaneous iliosacral screw insertion. The etiology of the pseudoaneurysm was likely multifactorial, including the injury (anterior-posterior compression pelvic fracture), prolonged coagulation parameters during administration of warfarin, and the percutaneous insertion of an iliosacral lag screw. A pseudoaneurysm of the superior gluteal arterial system should be included in the differential diagnosis of unexplained pelvic or buttock pain after a pelvic fracture.

Open pelvic fractures. A multicenter retrospective analysis

A marked discrepancy exists in the reported mortality rates in patients with open pelvic fractures, ranging from 4.8% to 50%. A retrospective review of patients with open pelvic fractures was performed at three centers. Thirty-nine patients with open pelvic fractures were identified; the average age was 32. The average injury-severity score was 29 (13-75). There were 10 (26%) deaths. Factors that correlated with mortality and morbidity were instability of the pelvic fracture and the presence of a rectal injury. Delay in performing diverting colostomy correlated with a poor outcome. Previously described methods of treatment are still valid; however, there is a need for re-emphasis of early diverting colostomy in the patient with a rectal or perineal injury. A classification system for open pelvic fractures is proposed in this article.

The hybrid ring tubular external fixator: a biomechanical study

OBJECTIVE: To measure and compare the mechanical properties in bending of the four-ring, and three-ring/one-tube hybrid external fixation frames. DESIGN. IN VITRO: measurements of the mechanical behaviour of ring and ring-tubular external fixation frames. In the latter, one ring of the full circular frame was replaced by one tube and Schanz screws. BACKGROUND: The mechanical properties of the classical Ilizarov four-ring external fixation frames has been compared to those of other external fixation frames by various authors. However, in clinical practice the hybrid fixation frame is being used with increasing frequency. Therefore the mechanical properties of the latter are of immediate interest and clinical value. METHODS: On explanted sheep tibiae with single and double osteotomies, frame stiffness in the four-point bending mode was measured at different K-wire tensions, comparing the values obtained from four-ring frames, to those of three-ring-tubular hybrid frames. These measurements were made under conditions of (a) bone distraction (BD), and (b) segment transport (ST), both at the initial and final stages of this procedure. RESULTS: In circular frames, frame stiffness in bending for increasing K-wire tension showed a Gaussian distribution both in distraction and post-ST with an optimum at 1000 N. In ring tubular hybrid frames, however, frame stiffness showed a more linear relationship to K-wire tension. CONCLUSIONS: In the four-ring Ilizarov external fixation frame, the exchange of one ring with one tube and one Schanz screw both reduced frame stiffness in bending and converted to linear its relationship to K-wire tension. RELEVANCE: Under clinical conditions, the use of a similar ring tubular hybrid external fixator allows the adjustment of frame stiffness in a simple and practical way. This is not the case with the original ring fixation frame.

Medial gastrocnemius transposition flap for the treatment of disruption of the extensor mechanism after total knee arthroplasty

We describe a modified technique for the salvage of a total knee arthroplasty after disruption of the extensor mechanism. Between January and December 1992, seven patients had reconstruction of the extensor mechanism with use of a medial or an extended medial gastrocnemius flap. Six of the seven patients were followed for a mean of thirty-three months (range, twenty-six to forty-one months) and were evaluated both preoperatively and postoperatively with regard to the knee and functional scores of The Knee Society as well as the range of motion, extensor lag, walking status, and patellar height. The seventh patient was lost to follow-up six months postoperatively and was excluded from the analysis of the results. Preoperatively, the knee and functional scores were 16 +/- 12.3 points and 12 +/- 12.1 points (mean and standard deviation), respectively; the mean range of motion was 70 +/- 44.0 degrees; and the mean extensor lag was 53 +/- 33.4 degrees. Postoperatively, the mean knee and functional scores improved to 82 +/- 12.4 points and 51 +/- 23.0 points, respectively; the mean range of motion improved to 100 +/- 21.8 degrees; and the mean extensor lag decreased to 24 +/- 18.8 degrees. After the procedure, all patients who previously had been dependent on a walker were able to walk about the community with or without a cane, and those who had been dependent on a wheelchair were able to walk with the assistance of a walker. Patellar height was measured according to the method of Insall and Salvati for the four patients who had a patella. Preoperatively, the patellar heights were grossly abnormal; postoperatively, they more closely approached accepted normal values for three of the four patients. Reconstruction of a complicated rupture of the extensor mechanism with use of a medial gastrocnemius transposition flap after total knee arthroplasty is a reliable option for treatment.

Cementless revision of total hip arthroplasty using the anatomic porous replacement revision prosthesis

This study reports the results of revision total hip arthroplasty with the Anatomic Porous Replacement Revision Hip System (Intermedics Orthopedics, Austin, TX) to investigate the value of cementless fixation. Sixty-six hips in 65 patients were followed for a mean of 4.7 years in patients with a mean age of 56 years. Thirty-six patients were categorized as Charnley class A, 16 as class B, and 13 as class C. Forty (61%) of the femurs were classified before surgery as having loss of bone distal to the intertrochanteric line. Thirty-two (48%) of the femurs required augmentation with demineralized strut cortical allografts, 5 (8%) required bulk femoral allografts, and 12 hips (18%) required acetabular allografts. Overall, 4 stems (6%) and 2 acetabular components (4%) required further revision surgery. The reason for further revision in 1 stem and both acetabular components was allograft failure. Fifty-six (85%) hips had excellent or good Harris hip scores. Ninety percent of hips had no or slight pain, and 90% allowed patients to walk with no or slight limp. Those hips that had hydroxyapatite coating added to the porous coating had statistically improved Harris hip scores for both pain and limp. Stable fixation was present in 95% of stems. Demineralized strut grafts healed in 30 of 32 hips. Thirty-nine of 44 noncemented revision sockets had no radiolucent lines and there were no loose components. Cementless fixation was effective for these hips.

Comparison of reconstruction nails for high subtrochanteric femur fracture fixation

Subtrochanteric osteotomies were created in 18 matched pairs of embalmed cadaveric femora. The femora were stabilized with a Synthes, Zimmer, or Richards second generation femoral reconstruction nail with retrograde blade or screws. The femoral pairs were randomly assigned to groups based on nails used: Synthes versus Zimmer, Synthes versus Richards, and Zimmer versus Richards. The reconstructions were cyclically loaded in bending for 2000 cycles and then loaded to failure. The mean stiffness of the Synthes, Zimmer, and Richards reconstructions was 17%, 40%, and 40% of the intact femora, respectively. The Richards construct was the strongest, and predominately failed by fracture at the distal interlocking screw hole. The Zimmer construct failed by bending of the nail at the osteotomy site and fracture of the proximal femoral shaft. The Synthes construct was the most flexible and least strong and failed by bending of the spiral, retrograde blade with concomitant fracture of the femoral neck. This study indicates that fixation of subtrochanteric femur fractures with a Synthes spiral blade or Richards or Zimmer reconstruction nails provides stable fixation for postoperative loading conditions. However, the Richards and Zimmer nails were able to withstand higher loads than was the Synthes nail before failure.

Supracondylar Fractures of the Femur

Successful management of the distal femoral fracture is possible with adherence to the basic principles of anatomic reduction, stable fixation, and early motion. Closed management can achieve these goals in selected patients, but most supracondylar femoral fractures are better treated with operative reconstruction. Implant selection is determined on the basis of the characteristics of the fracture, the bone quality, the needs of the patient, and the experience of the surgeon. Surgical options include the angled blade plate, compression-screw systems, condylar buttress plates, intramedullary nails, external fixation, and modular distal femoral replacement. The author reviews the indications and techniques for using these devices.

Results of arthroscopic versus open Bankart suture repair

The purpose of this study was to compare patients with anterior shoulder instability who were treated with an open Bankart procedure with those treated with an arthroscopic procedure. During a 3-year period, 43 patients (44 shoulders) were surgically treated. Thirty-four patients were available for followup. Eighteen shoulders had open Bankart procedure, and 16 shoulders were treated arthroscopically. Capsular laxity can be better assessed with the open procedure. A Bankart lesion was found in all the patients in both series. Average followup for Group 1 was 34 months, and for Group 2, it was 23 months. Group 1 had 83% good to excellent results with no recurrent dislocation or reoperation. Group 2 had 50% good to excellent results, and 50% fair to poor results with 3 recurrent dislocations and 4 recurrent subluxations that required second operation. The average loss of external rotation in Group 1 was not significantly greater than that in Group 2. Sixteen patients in Group 1 and 8 patients in Group 2 were able to return to their primary work or sport. Results of arthroscopic Bankart repair do not equal those of the open Bankart procedure for the rate of recurrence and postoperative range of motion. The followup reported is short, and more dislocations can be anticipated with longer followup.

The effect of anterior cruciate ligament graft fixation site at the tibia on knee stability: evaluation using a robotic testing system

Despite its current popularity and relative success, endoscopic reconstruction of the anterior cruciate ligament (ACL) using a bone-patellar tendon-bone (BPTB) graft has not yet been perfected. Using a recently developed robotic/UFS testing system, we assessed the overall stability of porcine knees following ACL reconstruction with different sites of tibial graft fixation--proximal, central, and distal. Testing of the intact knee was performed first to determine the normal anterior-posterior (A-P) displacements and in situ forces of the ACL under 110 N of anterior tibial loading of 30 degrees, 60 degrees, and 90 degrees of knee flexion. The knee was then reconstructed with a BPTB autograft, and the distal end of the graft was fixed sequentially at three different locations in each specimen--proximal, central, distal. A-P testing was repeated for each fixation site, and the resulting knee kinematics and the in situ forces of the grafts were compared to the intact case. The site of tibial fixation was demonstrated to have a significant effect on the resulting anterior displacement and internal rotation of the tibia as well as the in situ forces of the graft. Proximal fixation produced the most stable knee (A-P displacements reduced to 120% of intact at 30 degrees and 170% at 90 degrees), becoming significantly less stable with more distal fixation. These results suggest that proximal graft fixation may provide the most acute stability of the reconstructed knee.

Arthroplasty for arthritis and rotator cuff deficiency

Massive and irreparable loss of rotator cuff tendon integrity can be associated with the development of glenohumeral and acromiohumeral arthritis. Loss of glenohumeral instability provided by the rotator cuff may initiate and perpetuate this unique condition of the shoulder. Proximal humeral replacement arthroplasty is the preferred surgical treatment; special techniques of this procedure are presented. Patients are gratified by the durable restoration of comfort and, to a lesser extent, function.

Arthroscopic management of tibial plateau fractures: special techniques

Arthroscopic assessment and treatment of tibial plateau fractures has gained popularity in recent years. This article describes some maneuvers to facilitate the management of these fractures with the arthroscope. We use a 14-mm rounded curved periosteal elevator to manipulate fragments within the joint instead of using a probe. To facilitate visualization of fractures, we describe the use of loop sutures around the meniscus to retract the meniscus when there is a tear in the meniscus. We suggest the use of the arthroscope for directly viewing the interosseous space to be sure that any internal fixation devices remain outside the articular space. The use of these tactics will allow a faster, more accurate reduction with less radiation exposure in patients with displaced tibial plateau fractures.

Three-dimensional primary stability of cementless femoral stems

OBJECTIVE: This study investigates by means of a new bone-prosthesis interface motion detector whether conceptual design differences of femoral stems are reflected in their primary stability pattern. DESIGN: An in vitro experiment using a biaxial materials testing machine in combination with three-dimensional motion measurement devices was performed. BACKGROUND: Primary stability of uncemented total hip replacements is considered to be a prerequisite for the quality of bony ongrowth to the femoral stem. Dynamic motion as a response to loading as well as total motion of the prosthesis have to be considered under quasi-physiological cyclic loading conditions. METHODS: Seven paired fresh cadaveric femora were used for the testing of two types of uncemented femoral stems with different anchoring concepts: CLS stem (Spotorno) and Cone Prosthesis (Wagner). Under sinusoidal cyclic loading mimicking in vivo hip joint forces a new measurement technique was applied allowing for the analysis of the three-dimensional interface motion. RESULTS: Considerable differences between the two prostheses could be detected both in their dynamic motion and total motion behaviour. Whereas the CLS stem, due to the wedge-shaped concept, provides smaller total motions, the longitudinal ribs of the Cone prostheses result in a substantially smaller dynamic motion. CONCLUSIONS: The measuring technique provided reliable and accurate data illustrating the three-dimensional interface motion of uncemented femoral stems.

Functional results in total hip replacement in patients 65 years and older

Total hip arthroplasty in patients 65 years and older has been very durable in long term results. Eighty-nine hips in 79 patients were observed for 5 to 9 years to determine the importance of advancing age and deterioration of activity levels to durability of total hip replacement. The age of patients was 65 years or older at the time of surgery. A classification of function was used that graded activity level. During the average 6.24 years of postoperative followup, 22% of the patients died, 38% had medical problems that reduced their functional level, and 10% reduced their function because of their hip surgery. Hip related deterioration occurred only in those patients with a cementless stem. There was decreasing measured wear with increasing age; otherwise, neither age nor activity change in this study was related to loss of fixation of components, osteolysis, or bone remodeling. Increasing age and decreasing activity in patients 65 years and older does not seem to be the primary reason for durability of total hip arthroplasty in these patients. In this age group, the durability of hip replacement is related mostly to the quality of fixation.

Results of Ankle Arthrodesis for Treatment of Supramalleolar Nonunion and Ankle Arthrosis

Seven patients with supramalleolar nonunions after tibial plafond fractures underwent ankle arthrodesis combined with surgical treatment of the nonunion. Stabilization of the nonunion and the ankle consisted of medial and lateral plating for two hypertrophic cases and medial external fixation for five atrophic cases. Two of the atrophic nonunions were infected, and the distal tibia below the nonunion was resected and distraction osteogenesis from a proximal level was used to fill the resulting defect. Both the nonunion and ankle arthrodesis healed in six patients in an average of 7.9 months (range, 4-20 months). The nonunion failed to heal in one patient and required a below-knee amputation. The average cost of care was $66,491 per patient. Before surgery, the average patient ankle score was 25 (range, 15-50), and at a median of 35 months' follow-up the average score was 64 (range, 18-79 months). Three patients had scores in the "good" range, two in the "fair" range, one in the "poor" range, and one was rated a treatment failure. The SF-36 scores were significantly lower than age-matched population-based normal subjects. Limb salvage was possible in six of these seven patients, but the treatment times were long, complications frequent, and the cost of care high.

Arthroscopic-assisted allograft anterior cruciate ligament reconstruction in patients with symptomatic arthrosis

We reviewed the results of arthroscopic-assisted anterior cruciate ligament (ACL) allograft reconstruction in 40 patients who had advanced articular cartilage deterioration documented by arthroscopy during the reconstruction. A mean of 7 years had elapsed between the original injury and the reconstruction, and 102 prior operative procedures had been done in 34 of the 40 patients. A total of 64 articular cartilage lesions were noted; 34 knees had lesions in the medial or lateral tibiofemoral compartment. Postoperatively, all had immediate motion and early functional rehabilitation. The results were assessed using the Cincinnati Knee Rating System. At follow-up (mean, 37 months), significant improvements were found for pain, giving-way, and functional limitations with daily and sports activities (P < .01). Fifty-five percent had returned to mostly light athletics (avoiding high impact sports) based on our advice and were asymptomatic. The mean overall rating scores significantly improved (P < .0001, mean improvement 22 points). We concluded that the majority of patients in this study with chronic ACL rupture and post-traumatic arthrosis benefited short-term from arthroscopic-assisted ACL reconstruction.

Fatigue properties of a twelve-hole versus a five-hole intramedullary supracondylar nail

OBJECTIVES

To evaluate a design change intended to improve fatigue properties of Intramedullary Supracondylar nails (IMSC).

DESIGN

Fatigue testing was performed on 12-hole and 5-hole IMSC nails in 18 plastic-fiber composite femurs. Fractures were simulated by a 1 cm wide osteotomy. Nails were cycled until failure with femoral loads ranging from 133 N to 1869 N (30 to 420 lb.) for the 12 mm nails and 133 N to 1335 N (30 to 300 lb.) for the 11 mm nails. A simple finite element computer model (FEM) was also created to determine the difference in stress distribution between the two designs.

SETTING

All mechanical testing was performed using a servohydraulic test fram (MTS Systems, Minneapolis, MN). The FEM was performed using I-DEAS software (SDRC, Milford, OH) running on an Apollo 9000/735 workstation (Hewlett-Packard, Palo Alto, CA).

INTERVENTION

The nails were locked proximal and distally.

MAIN OUTCOME MEASUREMENT

The number of cycles to failure and the maximum tensile stress (FEM) was measured and compared between the two designs.

RESULTS

The 11 mm and 12 mm 12-hole nails failed at an average of 53,514 cycles and 102,433 cycles respectively. No nail failures were seen in the 5-hole design. The FEM showed a 400% increase in maximum tensile stress due to the transverse screw hole in the cannulated nail.

CONCLUSIONS

Elimination of screw holes at the level of a supracondylar metaphyseal defect significantly improves the fatigue life of the IMSC nail.

Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury

The results were reviewed for 259 patients who had open reduction and internal fixation of 262 displaced acetabular fractures within twenty-one days after the injury. Two hundred and fifty-five hips were followed for a mean of six years (range, two to fourteen years) after the injury; the remaining seven, which clearly had a poor result, were followed for less than two years. According to the classification of Letournel and Judet, associated fracture types accounted for 208 (79 per cent) of the fractures, with both-column fractures being the most common type (ninety-two hips; 35 per cent). Two hundred and fifty-eight hips were operated on with a single operative approach (Kocher-Langenbeck, ilioinguinal, or extended iliofemoral). The four remaining hips were operated on with a Kocher-Langenbeck as well as an ilioinguinal approach. The reduction was graded as anatomical in 185 hips (71 per cent). The rate of anatomical reduction decreased with increases in the complexity of the fracture, the age of the patient, and the interval between the injury and the reduction. The over-all clinical result was excellent for 104 hips (40 per cent), good for ninety-five (36 per cent), fair for twenty-one (8 per cent), and poor for forty-two (16 per cent). The clinical result was related closely to the radiographic result. The clinical result was adversely affected by associated injuries of the femoral head, an older age of the patient, and operative complications. It was positively affected by an anatomical reduction and postoperative congruity between the femoral head and the acetabular roof. Osteonecrosis of the femoral head was noted in eight hips (3 per cent), and progressive wear of the femoral head was seen in thirteen (5 per cent). Subsequent operations included a total replacement of seventeen hips (6 per cent), an arthrodesis in four (2 per cent), and excision of ectopic bone in twelve (5 per cent). These findings indicate that in many patients who have a complex acetabular fracture the hip joint can be preserved and post-traumatic osteoarthrosis can be avoided if an anatomical reduction is achieved. An increase in the rate of anatomical reduction and a decrease in the rate of operative complications should be the goals of surgeons who treat these fractures.

Special considerations in the athletic throwing shoulder

Overhead athletes are susceptible to a number of shoulder problems due to the repetitive nature and force needed to perform at a competitive level. Frequently, the rotator cuff becomes injured due to primary or secondary impingement. In young athletes, subtle instability is often the cause of rotator cuff tendinitis, but will frequently respond to a coordinated rehabilitation program. Older athletes are more likely to have rotator cuff injuries due to anatomic changes in the coracoacromial arch. This article outlines the mechanism of injury to the rotator cuff and our approach in dealing with shoulder problems in the overhead athlete.

Follow-up results 20 years after surgical treatment of habitual ventral shoulder luxation using the Eden-Lange technique

After undergoing an operation according to the Eden-Lange technique, 56 patients with recurrent anterior shoulder luxation were re-examined clinically at an average follow-up period of 20 years. The mean age of the patients at the time of the operation was 24.9 years; the ratio of male to female patients was 2.3:1. The Ellman score (maximum of 27 points), stability tests, reluxation rate and X-ray examinations served as re-examination criteria. The mean score for the Ellmann test was 18.3 points; 29 patients had ventral instability. In the meantime 11 shoulders had redislocated. Fifty-one patients had arthrotic alterations in the operated shoulder. Because of the unsatisfactory functional and radiographical results, the Eden-Lange technique can no longer be accepted as the only treatment of choice for anterior shoulder dislocation.

Results of the Müller acetabular reinforcement ring in revision arthroplasty

Between April 1984 and December 1987 a Müller acetabular reinforcement ring was employed in 98 revision cases (94 patients). Twenty-two patients died before follow-up evaluation. Forty-seven (66%) of the remaining 72 patients (49 of 75 hips) were examined after a mean of 6.4 years (range 5-9 years). Excluding those who died, the postoperative outcome of 69 patients is known. Migration was measured according to Sutherland by means of a digitising table. Cup position was determined by a new angle (beta) between the sacroiliacal line and a reference line. The reference line connects the centre of the femoral head with the intersection between the sacroiliacal and obturator lines. Aseptic and septic loosening required revision surgery in 2 cases each (4%). The postoperative beta angle showed a high correlation with migration (P = 0.001) as well as with radiolucencies (P = 0.001). In cases which required further revision, beta amounted to 44 deg (craniolateral position), and in stable cases up to 60 deg. A lateral and cranial position of a Müller acetabular reinforcement ring leads to high loosening rates. The beta angle accurately describes cup position, and its postoperative value is highly predictive for loosening.

Traumatic tears of the subscapularis tendon. Clinical diagnosis, magnetic resonance imaging findings, and operative treatment

The study population consisted of 14 shoulders in 13 consecutive patients with surgically confirmed isolated subscapularis tendon tears. In all but three patients, the mechanism of injury was traumatic hyperextension or external rotation of the abducted arm. All patients reported pain and weakness in the affected shoulder. Physical findings revealed limited passive range of motion at maximal internal and external rotation due to pain, weakness of internal rotation of the shoulder, and tenderness in the region of the intertubercular groove. However, these findings did not conclusively point to the subscapularis tendon as the site of injury. Preoperative interpretation of magnetic resonance imaging studies was used to diagnose tears of the subscapularis tendon in 14 shoulders and biceps tendon subluxation or dislocation in 6 shoulders. On arthroscopic examination, one patient was found to have a partial-thickness tear that was treated with arthroscopic debridement. Six shoulders had full-thickness tears of the subscapularis tendon, and seven shoulders had full-thickness tears associated with concomitant biceps tendon pathologic conditions, including subluxation, dislocation, or rupture. The full-thickness subscapularis tendon tears were repaired via an open anterior approach to the shoulder through the deltopectoral groove. Associated biceps tendon injuries were treated with tenodesis of the tendon to the intertubercular groove. Our early followup results have shown that, with proper diagnoses and surgical treatments, patients have greatly decreased pain and marked improvement in shoulder function.

Massive rotator cuff tears: debridement versus repair

In many studies, short-term and midterm results of debridement seem to show satisfactory results. However, the three long-term studies currently available all report that these initial results deteriorate significantly with time and are not acceptable. If debridement is considered, careful preoperative and intraoperative evaluation as discussed by Burkhart should be followed. We believe an adequate understanding of the anatomic subtleties, pathologic changes, biomechanical forces, and advanced reconstructive techniques allows repair to be performed in most, if not all, rotator cuff tears of the shoulder. The findings of the study described herein indicate that repair of these tears is the treatment of choice.

Biomechanics of the rotator cuff

Thorough understanding of rotator cuff mechanics is important for effective treatment and/or prevention of cuff injuries. This understanding is achieved through knowledge of normal cuff structure and mechanics. Only then, can the effects of injuries and pathologic processes on normal cuff function be carefuly assessed. Rotator cuff structures are viewed and analyzed on a number of different levels. This article presents current knowledge of rotator cuff mechanics through review of cuff structure and anatomy, corocoacromial arch structure and biomechanics, and biomechanical models.

Molecular identification of foreign inclusions in inflammatory tissue surrounding metal implants by Fourier transform laser microprobe mass spectrometry

Fourier transform laser microprobe mass spectrometry (FT LMMS) is a novel technique for micro-analysis of solids with a lateral resolution in the 5 microns range. One of the major advantages of the technique is the capability to perform characterisation of the molecular composition of both organic and inorganic compounds. The information is directly deduced from the signals without the aid of reference spectra. FT LMMS was applied to the characterisation of black tissue fragments in a biopsy from a patient, in which a constrained condylar nodular knee system was implanted ten years ago. The tissue contained numerous foreign giant cells with a black non-birefringent pigment in their cytoplasm. FT LMMS analysis allowed us to detect directly by means of molecular signals, that the debris consisted primarily of titanium oxide and not metallic titanium, while the implant itself only contained titanium.

Return to sport after a Bankart operation of the shoulder using the Mitek anchor system

Sixteen athletes suffering anterior instability of the shoulder after primary or recurrent traumatic anterior dislocation were followed for a mean of 23.9 months after an open Bankart operation using Mitek anchors. Nine patients resumed sports an average of 4.4 months postoperatively, while the remaining seven patients did not return to sports at all. By comparing the group of athletes who had resumed sports and the group who had not, we found in the former group a lower mean age, a higher number of athletes who had inflicted their first anterior dislocation during sports and a larger number of people injured on the dominant arm. However, none of the above-mentioned differences were statistically significant, and there were no differences in range of motion, degree of disability or stability of the operated shoulders in the two groups: returned vs. not-returned to sports. All the athletes performing sports at elite-level returned to sports, whereas all the recreational athletes did not. Among the reasons for not resuming sport, 71% gave sociopsychological reasons such as anxiety or lack of time. Two athletes (12.5%) had suffered redislocations after 12 and 19 months, respectively. No complications or other problems related to the use of Mitek anchors were observed.

Management of patella fractures associated with central third bone-patella tendon-bone autograft ACL reconstructions

Patella fractures are an acknowledged complication of cruciate ligament reconstructions that use bone-tendon-bone autografts. Two fracture patterns are seen: a nondisplaced longitudinal patellar fissure fracture recognized interoperatively and the classic displaced transverse fracture that disrupts the extensor mechanism. Rigid fixation techniques are described for each fracture type that minimally affect rehabilitative efforts.

Outcome after pelvic ring fractures: evaluation using the medical outcomes short form SF-36

Fifty-five multiply injured patients with operatively treated unstable pelvic fractures were evaluated for patient-oriented outcome measures. Forty-six adult patients were eligible to complete the SF-36 medical outcome score and completed the SF-36 eight scale medical outcome score by postal questionnaire at a mean follow up to 2 years. The average Injury Severity Score of the eligible patients was 17.5. The average age of the patients was 32 years and 8 months. Fractures were classified by the Tile classification and there were 13 type B and 33 type C pelvic fractures. Seventy-six per cent of patients responded to the surgery. There was a 14 per cent impairment in physical outcome score and a 5.5 per cent impairment in mental outcome score compared with the normal population. The physical and mental outcome of multiply injured patients with pelvic fractures can be measured objectively.

Fixation of segmental subtrochanteric fractures. A biomechanical study

Segmental subtrochanteric fractures have been associated with high rates of malunion, nonunion, and implant failure. Although the use of second generation intramedullary nails with proximal interlocking in the femoral head has been advocated for these fractures, shaft fractures at the tip of short second generation intramedullary rod nails in clinical studies raise concerns about the mechanical suitability of these implants. No biomechanical data are available on the strength of fixation and mode of failure of these newer implants. This study compares the strength and failure mode of segmental subtrochanteric fractures stabilized with 3 current implants. Eighteen anatomic specimen femurs were obtained. The 3 implants tested were the Russell-Taylor reconstruction nail, a short intramedullary hip screw, and a long intramedullary hip screw. Each femur was instrumented and a segmental subtrochanteric fracture was created. The femurs were loaded in a Materials Testing System. The strength of the reconstruction nail group (2869 +/- 210 N) was significantly greater than for the short intramedullary rod hip screw (2330 +/- 490 N), and the long intramedullary rod hip screw (2181 +/- 244 N). The failure modes for the implants were: screw cut out of the femoral head for the reconstruction nail; fracture of the femoral shaft for the short intramedullary hip screw, and implant bending for the long intramedullary hip screw. This study suggests that the reconstruction nail is the superior implant for segmental subtrochanteric fractures of those tested. Implant bending and shaft fractures at lower loads make the 2 intramedullary rod hip screw implants less suitable.

Treatment of supracondylar femoral fractures with a retrograde intramedullary nail

From August 1992 to January 1995, 24 patients with 26 supracondylar femoral fractures were treated with a retrograde intramedullary nail. There were 22 patients with 24 nails available for review. Eight fractures were open and 13 were intraarticular fractures. There were a significant number of associated injuries. The average followup interval was 18 months (range, 4-36 months). All fractures healed by 4 months, (average, 3 months). Only 1 patient required bone grafting. There were no implant failures or superficial or deep infections. One malunion occurred. Average knee range of motion was 104 degrees. A previously described rating scale was used to evaluate function. There were 4 excellent, 16 good, 2 fair, and 2 poor results. The supracondylar nail provides rigid internal fixation for rapid healing and comparable functional outcomes to lateral fixation devices with significantly less soft tissue dissection.

Posterior rod system of the cervical spine: a new implant allowing optimal screw insertion

A new implant system for posterior stabilisation of the occipitocervical junction and the cervical and upper thoracic spine is described. The system consists of rods and clamps. For fixation to the occiput, the 3.5-mm titanium rod goes over into a 3.5-mm AO-reconstruction plate. Several clamps may be fixed to the rod at variable intervals, depending on the anatomical situation and the specific needs. Five types of clamps with different angulations of the screw hole with respect to the rod allow optimal screw insertion and fixation of the rod at all levels instrumented. Locking screws may be used to allow fixed stabilisation of the screw to the rod. Hooks for sublaminar anchoring, connectors to other rods and a cross-linking device are also available. Unlike plate fixators, the system allows screw insertion at any angle and at any interval. Therefore, optimal screw insertion is possible in any anatomical situation. Furthermore, ample space is available for bone grafting of the posterior aspect of the lateral masses. This is especially important following a laminectomy. Preliminary clinical results in 20 patients are presented; no complications have been seen to date. Our system has recently been approved as an AO-implant.

Natural history of femoral focal osteolysis with proximal ingrowth smooth stem implant

Focal femoral osteolysis has become a prominent cause of failure of total hip arthroplasty. Femoral focal osteolysis is studied in 185 hips with a patched porous-coated titanium femoral stem. Seventy-two hips had osteolysis and 113 did not. Seventy-one percent of osteolysis is evident on radiographs by 6 months to 5 years after surgery. The location is most commonly seen on an anteroposterior radiograph, with proximal osteolysis most common and the initial size of defects being greatest in zones 2, 3, 5, and 6. Progression of size is slow, with each focal defect averaging 0.89 mm/y. Progression of bone loss occurs more commonly with the occurrence of new defects rather than extension of an existing defect. Focal osteolysis was directly correlated with the amount of polyethylene wear. Osteolysis is more likely when linear polyethylene wear exceeds 0.2 mm/y or volumetric wear exceeds 150 mm3/y or when the patient is below age 60. Accelerated wear and osteolysis occur most often when the fixation of the arthroplasty is poor.

Clinical and radiographic outcome of a cementless, titanium, plasma spray-coated total hip arthroplasty femoral component. Justification for continuance of use

Between 1984 and 1986, 177 nonconsecutive, primary total hip arthroplasties were performed in 150 patients using the Mallory-Head Porous femoral component (Biomet, Warsaw, IN) inserted without cement. Average time to follow-up evaluation for the entire population (including all early revisions) was 76 months (6.3 years). There were 10 revisions (6%) with an average time to revision of 50 months (4.2 years). Two revisions were for component undersizing; three revisions were for aseptic loosening; four revisions were for acetabular component failure and one revision was due to a femoral fracture secondary to trauma. At the most recent follow-up visit, the average Harris hip score for all hips increased from 41.5 before surgery to 86.8 (P < .001). Radiographic assessments yielded an average Engh fixation score of 20.7. The Kaplan-Meier survival estimate for the average time to follow-up evaluation was 0.98. Based on our patient selection criteria and excellent intermediate clinical and radiographic results, the initial design strategies of the Mallory-Head Porous femoral prosthesis have been confirmed.

Talar neck fractures: anatomic considerations for posterior screw application

The bony window available for posterior screw placement in the talus and the morphology of the talar neck were studied in 50 dry tali. In addition, 12 cadaver specimens were used to study the posterolateral approach. The bony window was bounded medially by the lateral tubercle of the posterior process of the talus, laterally by the fibular facet, superiorly by the trochlear articular surface, and inferiorly by the posterior calcaneal facet. The average vertical thickness at 2-mm increments was recorded across the talar neck to define the bony mass available for screw insertion. The smallest thickness of the talar neck was at a point 2 mm medial to the lateral border. The thickness progressively increased in a medial direction. The superior talar neck surface was found to have an average width of 18.4 +/- 1.6 mm. The angle formed between the superior and lateral surfaces of the talar neck averaged 29.3 degrees, which would account for the better delineation of the lateral border of the neck under fluoroscopy of the talus with the foot in pronation. The diameter of the screw in relation to the window height should be considered.