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Fifty-seven consecutive patients (58 knees) with an acute, isolated, posterior cruciate ligament (PCL) injury were treated nonoperatively. Clinical, radiographic, and functional assessment was performed at a mean follow-up of 6.9 years (range 2 to 19.3 years) after the initial diagnosis. At the time of initial documentation of the injury, the posterior drawer test was grade A in 17 knees and grade B in 41 knees. The mean preinjury Tegner activity level was 7 (range 4 to 10). At latest follow-up, 38 knees had no pain, 14 had mild pain, and 6 had moderate pain on exertion. Fifty-four knees had no swelling, 3 had mild, intermittent swelling, and 1 had a moderate swelling on exertion. The posterior drawer test was grade A in 14 knees and grade B in 44 knees. The mean Lysholm-II knee score was 85.2 points (range 51 to 100 points) and the mean Tegner activity level was 6.6 (range 3 to 10). Based on Lysholm-II knee scoring system, the results were excellent in 23 knees (40%), good in 30 knees (52%), fair in 2 knees (3%), and poor in 3 knees (5%). No statistically significant correlation (p = 0.097) was seen between the grade of PCL laxity and Lysholm-II knee score. Plain radiographs showed mild (grade I) medial compartment osteoarthritis (OA) in 7 knees, and moderate (grade II) medial compartment OA in 3 knees. Mild patellofemoral OA was seen in 4 knees. We believe that most patients with acute, isolated PCL injuries do well with nonoperative treatment at a mean follow-up of 6.9 years. The level of evidence for this retrospective cohort study is level III.

The material properties of the anterior cruciate ligament (ACL) in female rats with normal estrous cycles were compared to those regulated by oral contraceptive steroids. Forty female Sprague–Dawley rats were divided into two groups: an experimental group received daily ethinylestradiol and levonorgestrel in a dosing model designed to simulate a typical oral contraception regime in humans, while a control group received daily oral placebo. After eight cycles, six rats from each group underwent daily phlebotomy to measure serum estradiol and progesterone levels over the course of a single 5-day estrous cycle. Significant differences between groups were found for the area under the curve of blood progesterone levels versus time over the length of the estrous cycle (P = 0.02). After 12 cycles, the rats were euthanized and one femur-ACL-tibia complex from each animal was dynamically loaded to failure. The ACLs from the rats in the experimental group had significantly decreased average and tangent stiffness, (P = 0.002 and 0.0001, respectively), and significantly increased elongation (P = 0.002) and total energy absorbed (P = 0.03), or greater toughness than controls. In rats, it appears that the administration of reproductive hormones designed to simulate typical oral contraception in humans alters the mechanical properties of the rat ACL.

Background Exact reconstruction of an osteochondral defect by autogenous transplantation (mosaicplasty) is difficult given the variation in joint surface contour. Clinical and experimental studies do not show the extent to which incongruity can be tolerated in autografting. Hypothesis Grafted articular cartilage will hypertrophy to correct the incongruity created by recession of the transplanted surface. Study Design Controlled laboratory study. Methods To test the response of grafts to incongruities, osteochondral autografts were transplanted from the trochlea to the femoral condyle in adult male sheep stifle joints. In groups of 6 animals, graft surfaces were placed flush, countersunk 1 mm or countersunk 2 mm, then histologically analyzed 6 weeks after surgery. Cartilage thickness, condition of the articular surfaces, and preservation of hyaline characteristics were the primary features compared. Results Bony union, vascularization, and new bone formation were present in all grafts. Cartilage-to-cartilage healing did not occur. In flush specimens, cartilage changed minimally in thickness and histologic architecture. The specimens countersunk 1 mm demonstrated significant cartilage thickening (54.7% increase, P < .05). Chondrocyte hyperplasia, tidemark advancement, and vascular invasion occurred at the chondroosseous junction, and the surface remained smooth. Cartilage necrosis and fibrous overgrowth were observed in all grafts countersunk 2 mm. Conclusions Minimally countersunk autografts possess a capacity for remodeling that can correct initial incongruities while preserving hyaline characteristics. Grafts placed deeper do not restore the contour or composition of the original articular surface. Clinical Relevance If preservation of normal hyaline cartilage is the objective, thin grafted articular cartilage can remodel, but the tolerance for incongruity is limited and probably less than that reported for an intra-articular fracture.

Meniscal tears in children and adolescents are uncommon but well-recognized injuries. Because meniscal tears and other more common acute injuries to the skeletally immature knee—such as fractures and patellar dislocations—typically present with hemarthrosis, careful diagnosis including histo

The interference screw is a reliable method used to secure tendon to bone and bone to bone in ligament reconstruction. Historically, metal interference screws have been used for this purpose in both anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction. However, several problems associated with the use of metal interference screws have led to the increasing use of bioabsorbable implants. Poly-L-lactic acid (PLLA) biodegradable interference screws have been used successfully for graft fixation in ligament reconstruction. Although adverse reactions have been reported with the use of biodegradable implants, late screw breakage is rare. To our knowledge no case exists of late screw breakage with bioabsorbable interference screws used in ligament reconstruction. We present one case in the setting of an ACL reconstruction and one with combined PCL and posterolateral corner reconstruction.

Recognition of posterolateral rotatory instability (PLRI) and identification of the anatomic structures of theposterolateral region of the knee and their contribution to stability has occurred recently; therefore, surgical techniques to address these problems are evolving.

Purpose: The purpose of this study is to better understand the function of the popliteomeniscal fasciculi and their relationship to the popliteus tendon and the lateral meniscus by describing these structures during embryonic development. Type of Study: Anatomic dissection and histologic evaluation. Methods: Twelve fresh-frozen lower extremity specimens (6 paired limbs) from second and third trimester human fetuses were obtained from spontaneous abortions. Each specimen was fixed in formalin and decalcified in 9.0% nitric oxide. The specimens were prepared by removal of all skin and most of the soft tissues before dissection of the lateral meniscus, parts of the posterolateral joint capsule, and the popliteus tendon and muscle. The right-side specimens were sectioned in the transverse plane, and the left-side specimens in the coronal plane. Histologic sections were prepared with H&E and Masson's trichrome stains. Light microscopy was used to evaluate the lateral meniscal attachment, with detailed attention to the popliteomeniscal fasciculi. Results: The close interrelationship of lateral meniscus and popliteus tendon, especially during embryologic development, does give a better understanding how the fasciculi stabilize the lateral meniscus and allow the popliteus tendon to function as a retractor of the lateral meniscus. The fasciculi consist of 3 layers including a dense collagen layer, a vascular layer, and a synovial or capsular layer. Conclusions: During embryologic development, the fasciculi appeared to provide a vascular supply to the lateral meniscus adjacent to the popliteal hiatus where the meniscus is devoid of capsular attachments. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 1 (January), 2001: pp 14–18

Unstable pelvic ring disruptions are often associated with significant morbidity and mortality, especially in patients with multiple injuries. Early pelvic fixation provides stability and should diminish ongoing hemorrhage. A simple anterior single-pin pelvic external fixator can be applied rapidly and accurately to stabilize pelvic ring injuries as a part of the initial patient resuscitation of such patients. Simple anterior pelvic external fixation (SAPEF) frames can be used as either temporary, definitive, or supplementary fixation depending on the pelvic injury pattern.Over a 32-month period, 41 patients with unstable pelvic ring disruptions were stabilized using a simple anterior pelvic external fixator. Eight patients had open pelvic ring injuries and 13 others had genitourinary system disruptions. Fluoroscopic imaging was used to insert all of the fixation pins into the iliac crest between the iliac cortical tables to a depth of at least 5 cm. Each patient had closed manipulative reduction of the pelvic ring using external methods before SAPEF application.One patient died less than 24 hours after injury because of torrential hemorrhage. Clinical evaluations and serial radiographs, including postoperative computed tomographic scans, were available for the other 40 patients postoperatively. Seventy-five of the 80 (94%) pins were completely contained between the iliac cortical tables, according to the computed tomographic scans. The initial pelvic closed reductions were maintained until the fixators were removed in 37 of 40 patients (93%). Only one deep pin track infection developed, mandating early frame removal and intravenous antibiotic therapy.Simple anterior pelvic external fixation can be applied rapidly using fluoroscopic guidance to direct accurate pin insertion and closed manipulative reduction of the pelvis. Depending on the specific pelvic ring injury pattern and clinical scenario, SAPEF can serve as a resuscitative temporary fixation device, as definitive pelvic treatment, or as a supplement for pelvic internal fixation implants.

In this study, we compared a study group of 20 patients who underwent anterior cruciate ligament (ACL) reconstruction with hamstring autografts using a 1-incision endoscopic technique verses a control group of 20 patients using a 2-incision technique. The patient groups were compared based on increase of bone tunnel diameter seen radiographically, physical examination, and arthrometer measurements. The 1-incision technique differed from the 2-incision technique in 2 ways: an EndoButton femoral fixation system and drilling of the femoral tunnel through the tibial tunnel (transtibial). This study shows that the majority of tunnel diameter measurements for the 1-incision ACL reconstruction technique were greater than those of the 2-incision ACL reconstruction technique using autologous hamstring tendons, at both 3 and 12 months of follow-up. Between 3 and 12 months follow-up, there was no statistical differences in tunnel enlargement between the 2 groups of patients. The measured tunnel enlargement, therefore, would have occurred before the 3-month follow-up. There was no significant difference in the Lachman or arthrometer testing in either group of patients at the termination of this study. This indicates that, although tunnel expansion is significant, the increased expansion is not related to increased knee laxity in the first year.

Three patients sustained a Schatzker type II depressed lateral tibial plateau fracture and a tear of the lateral meniscus following a valgus injury to the knee. An arthroscopically-aided reduction of the articular surface was performed. This was followed by an autogenous iliac crest buttress graft with cancellous screw fixation. The meniscal tear was abrased with a rasp or a shaver. An arthroscopic repair of the lateral meniscus during the same session was performed. Clinical follow-up, including MR imaging of the knee at 68 months (range 60–74 months), showed an excellent clinical result and a completely healed meniscus in all patients. Arthroscopic meniscal repair in combination with arthroscopically-aided reduction of a depressed lateral tibial plateau fracture is technically possible. Restoration of the anatomy of both tibial plateau and lateral meniscus will optimize the outcome.

The purposes of this study were to determine whether any of the commonly recommended osteochondral donor sites are nonarticulating throughout a functional range of knee motion, and to determine the differential contact pressures for these sites. Ten commonly recommended sites for osteochondral harvest were evaluated with pressure-sensitive film through a functional range of motion with a model that simulated nonweightbearing resistive extension of the knee. All 10 donor sites demonstrated a significant contact pressure through 0° to 110° of knee motion. The different color density measurements between donor sites were also significant. Although donor sites 1, 2, 9, and 10 demonstrated significantly less contact pressure than the sites with the greatest contact pressure, the difference in mean pressures was small. No osteochondral donor site tested was free from contact pressure. It is currently unknown whether articular contact at these osteochondral donor sites will lead to degenerative changes or any other problems.

Peripheral lateral meniscal tears are amenable to arthroscopic meniscal repair. However, the posterolateral aspect of the lateral meniscus adjacent to the popliteus tendon is devoid of penetrating peripheral vessels and therefore difficult to heal. A complete radial split at this site is usually treated with total meniscectomy. We report five cases of a tear of the posterolateral aspect of the lateral meniscus anterior to the popliteus fossa. All patients had a radial split that extended to the popliteus tendon. In all cases, the repair was enhanced with a fibrin clot. Second-look arthroscopy showed that healing of the periphery occurred in all of the cases. All patients returned to their initial level of sports activity. Three of five patients were available for follow-up at an average of 71 months, and magnetic resonance imaging was performed at that time to assess the previously repaired meniscus. All menisci were fully healed and showed no further signs of degeneration. The ability of an exogenous fibrin clot to stimulate and support a reparative response in the avascular portion of the meniscus may represent a potential method of repair. Awareness of the relatively low healing potential of this zone and enhancement of healing opportunities should improve outcome.

A clinical and cadaveric example show the EndoButton (Acufex Microsurgical Inc, Mansfield, MA), used for anterior cruciate ligament endoscopic fixation, flipping outside the extensor mechanism or vastus lateralis rather than flipping directly outside the lateral femoral cortex. This pitfall was caused by overdrilling the femoral socket beyond the recommended 6 mm and overadvancing the EndoButton beyond the required depth to flip the EndoButton. Overdrilling the femoral socket to a depth of 10 mm still allows the EndoButton to rest properly on the cortex without soft tissue interposition. Increasing angles of knee flexion at the time of Endobutton placement decrease the safe distance beyond the lateral femoral cortex for flipping without soft tissue interposition. There is also potential to flip the EndoButton within the substance of the vastus lateralis, but the flipping action is blunted and not discrete.

In an attempt to understand better the contribution of the anteroinferior and posterosuperior popliteomenis cal fasciculi to lateral meniscus stability, we objectively evaluated the stability of the lateral meniscus before and after sequentially sectioning these fasciculi. In the biomechanical model, we attempted to account for the inherent limitations of arthroscopic evaluation of lateral meniscal stability. When the fasciculi were intact, the average lateral meniscal motion with a 10-N load was 3.6 mm. When the anteroinferior fascicle was dis rupted, the average lateral meniscal motion with a 10-N load was 5.4 mm. The mean increase in motion from the intact state was 1.8 mm or 50%, which was significant. When both fasciculi were disrupted, the average lateral meniscal motion with 10-N load was 6.4 mm. The mean increase in motion from the intact state was 2.8 mm or 78% and from the single fascicle disruption state was 1.0 mm or 18%, both differences were significant. The meniscus did not become locked with any of these loading trials, and it spontaneously reduced to the original position when unloaded. Both fasciculi make significant contributions to meniscal sta bility. Even though the meniscus never became locked in the joint when loaded during this study, with the variable loads seen with normal activities mechanical symptoms might be expected when meniscal motion is almost double. An increase in lateral meniscal motion at the time of surgery may aid in the diagnosis of fasciculi disruption, despite normal meniscal structure on magnetic resonance images and at arthroscopic visualization.

A rare case of Candida infection after revision total knee arthroplasty that was treated medically, without amphotericin B or resection arthroplasty, is reported. This case occurred in an elderly patient without predisposing medical problems. The patient was treated with only a suppressive dose of ketoconazole. The patient was last evaluated 6 years after the revision surgery and had no problem or signs of infection. Factors contributing to successful medical treatment in this case were likely the routine debridement at revision surgery and the patient's intact immune system.

We hypothesize that disruption of the fascicular attachments between the popliteus and lateral meniscus can result in gross instability of the meniscus producing locking of the knee. This study brings attention to the importance of the clinical examination, and the need for clinical correlation to magnetic resonance (MR) studies. We report on three patients referred with the history of mechanical locking episodes of their knee. Initial MR examinations were all read as normal before referral to our institution. On close review of these MR examinations, popliteomeniscal fascicular disruption could be seen in each case. Each of these patients had arthroscopic-repair of these meniscal detachments. At 1-year follow-up, all patients had resolution of mechanical symptoms. Each patient had confirmation of their repair with repeat arthroscopy or MR and arthrographic examinations. An anatomic specimen was used to identify the popliteus muscle and tendon, the lateral meniscus, the antero-inferior popliteomeniscal fascicle, and the postero-superior popliteomeniscal fascicle attachments. MR images of the same anatomic specimen show both superior and inferior fasciculus attachments to the capsule. MR examples of the intact and disrupted antero-inferior and postero-superior popliteomeniscal fasciculi have been correlated to anatomic specimens to help familiarize the orthopaedic surgeon with these important stabilizing structures.

Potential complications due to iliosacral screws are numerous. Problems occur as a result of poor preoperativeplanning, inadequate intraoperative fluoroscopic imaging, inaccurate posterior pelvic reductions, posterior pelvic anatomical variations, and other reasons. Local nerve or vascular structures are at risk during screw insertions, and fixation failures are associated with insufficient anterior and posterior pelvic stability. Inadequate fixation may result in screw failure and/or delayed or nonunions. Removal of intact or broken screws can also be difficult.

Pelvic ring disruptions are challenging management problems for the orthopedic surgeon. Early hemorrhage, permanent nerve injury, and late pain caused by residual pelvic deformity are some of the many complicating factors. A variety of treatment alternatives are available to stabilize the disrupted pelvic ring. Each technique has inherent advantages and problems.

The optimal method of internal fixation of basicervical femoral neck fractures is controversial. This area represents a transition zone between the intracapsular femoral neck fracture, usually fixed with multiple cancellous screws, and the extracapsular interochanteric fracture, fixed with a sliding screw device [sliding hip screw (SHS)] and derotation screw (DRS) device. The authors' specific aim was to biomechanically compare these two methods of fixation in a cadaveric model of a basicervical femoral neck fracture with posteromedial comminution.The authors compared the average peak force during cyclic loading and the maximum axial force sustained by matched pairs of specimens stabilized with either fixation and subjected to axial and torsional loading while flexing and extending the hip. The average peak force was defined as the mean of the peak force values measured in each loading cycle with the maximum displacement of the materials tester actuator the same for each cycle (displacement control) as opposed to the maximum force being held constant (load control).The cancellous screw group maintained a significantly lower average peak force, 470 Newtons (SD = 145 Newtons), compared with 868 Newtons (SD = 186 Newtons) for the SHS and DRS composite group (p0.01). Similarly, the cancellous screw group demonstrated a lower ultimate load to failure, 1,863 Newtons (SD = 475 Newtons) compared with 3,557 Newtons (SD = 215 Newtons) for the SHS and DRS composite group (p0.01).The results support the use of an SHS and DHS composite compared with three cancellous screws in the treatment of unstable basicervical femoral neck fractures.

Specimens of articular cartilage from human knees with gross evidence of malacia (dull appearance and/or softness) or fibrillation (exposed fibrous strands and/or staining with India ink) were prepared for scanning electron microscopy (SEM) and compared to cartilage from apparently intact regions. Vertical cryofractures were made through the center of each specimen, so the matrix collagen structure and its relationship to surface features could be examined. Soft, dull, malacic cartilage was characterized by the presence of numerous clefts among the collagen fibers within the most superficial region of the cartilage. In one form of this condition, these clefts did not extend through the articular surface. In a second form, usually observed where the tangential zone was normally thin or absent, the free ends of radial collagen fibers were exposed, but the deeper layers were intact. Two forms of fibrillation were also identified. The first is created by separation of the superficial lamellae which curl up from the tangential layer and form frondlike projections above the normal plane of the joint surface. In the second, deep radial fibers are exposed by vertical fissures. This second form is associated with advanced damage to the joint. The early stages of cartilage failure are characterized by debonding among the major collagen fiber tracts. This process may initiate in the deep tangential zone where the radial fibers cross into the surface. The patterns of the degenerative changes are dictated by the original architecture of the collagen matrix. The microscopic findings do not correlate adequately with conventional gross grading. SEM provides useful information about injured articular cartilage.

Early reconstruction of the thumb carpometacarpal (CMC) joint after traumatic dislocation, when instability is present, may decrease the incidence of recurrent instability and post-traumatic joint degeneration. We report two retrospective cohort groups of patients who had sustained a traumatic thumb CMC joint dislocation. The first 8 patients, group A, were treated with closed reduction and pinning. Because the results were unsatisfactory with 4 patients, requiring revision surgery for recurrent instability in 3 and degenerative arthritis in 1, the treatment plan was changed to open reduction with a flexor carpi radialis weave, group B. The 9 patients in group B underwent early (an average of 7 days after injury) ligamentous reconstruction to decrease the incidence of joint damage from recurrent instability and improve long-term functional results. For patients in group B with a minimum follow-up period of 2 years, pain was not a major problem, and range of motion and grip strength were essentially preserved. The functional variables affected most in both groups were thumb abduction, which was decreased by 10%, and pinch strength, which was decreased by 13%, in group B, as compared to 20% and 19%, respectively, for the patients in group A. Radiographically, the joint space was slightly narrowed (Eaton stage II) in 3 cases in group B; however, these were asymptomatic. In group A, 5 patients demonstrated degenerative changes of the CMC joint (3 Eaton stage II, 2 stage III), and 3 patients were symptomatic after treatment.

Closed manipulative reduction and percutaneous fixation of a displaced sacral fracture is a treatment alternative that offers several advantages. The fracture is reduced and stabilized without an extensile surgical exposure. The risks of surgical wound problems, especially infection, are lessened. Operative and anesthesia times are decreased by using percutaneous techniques of reduction and fixation. Blood loss is also minimized by the percutaneous procedure. Sacral nonunion after this technique is rare. The procedure is dependent on quality fluoroscopic pelvic imaging, a thorough understanding of the posterior pelvic anatomy and early operative intervention, especially in patients with severe posterior pelvic deformities.

We treated 17 knees in 15 patients with severe ligament derangement and dislocation by open repair and reconstruction. We assessed the competence of all structures thought to be important for stability by clinical examination, MRI interpretation, and surgery. Our findings showed that in these polytrauma patients clinical examination was not an accurate predictor of the extent or site of soft-tissue injury (53% to 82% correct) due mainly to the limitations of associated injuries. MRI was more accurate (85% to 100% correct) except for a negative result for the lateral collateral ligament and posterolateral capsule. The detail and reliability of MRI are invaluable in the preoperative planning of the surgical repair and reconstruction of dislocated knees.

Associated urological and orthopedic injuries of the pelvic ring are complex with numerous potential complications. These patients are treated optimally using a team approach. The combined expertise is not only helpful initially when managing these difficult patients, but also later as problems develop. This study describes a treatment protocol and reports the early results of 23 patients with unstable pelvic fractures and associated bladder or urethral disruptions, or both, treated surgically with open reduction and internal fixation of the anterior pelvic ring injuries at the same anesthetic and using the same surgical exposure as the urethral realignments or bladder repairs or both. Early complications occurred in four patients (17%): one patient sustained a fifth lumbar nerve injury caused by the pelvic reduction procedure, and three patients had anterior pelvic internal fixation failures. Late complications occurred in eight patients (35%). There was one deep wound infection (4.3%) that presented 6 weeks after injury. Late urological complications occurred in seven patients (30%). Four of the nine male patients with urethral disruptions had urethral stricture after their primary urethral realignments (44%). Three of the 18 male patients admitted to impotence (16.7%). One of the three had a residual thoracic paraplegia caused by a burst fracture. One of the five female patients had urinary incontinence and required a bladder suspension operation to restore normal function (20%). A low infection rate can be expected despite the use of internal fixation. Early urethral "indirect" realignments avoid more difficult delayed open repairs; however, late urological complication rates are still high. Early "direct" bladder repairs are easily performed at the time of anterior pelvic open reduction and internal fixation. Suprapubic tubes are not necessary to adequately divert the urine when large diameter urethral catheters are used in these patients.

We tested prospectively for hepatitis C virus (HCV) in one orthopaedic surgeon's operative practice for one year. Of 425 consecutive patients, 19 (4.5%) were positive for HCV infection using a second-generation screening assay. The highest correlation with a positive test was the presence of tattoos and the second highest was intravenous drug abuse, but only after a second interview, since most patients did not report this risk on the initial questionnaire. Based on the criteria of the US Public Health Services algorithm, nine (47%) of the patients with a positive initial screening test or 2.2% of the 425 patients, had hepatitis C (both anti-HCV-positive and elevated alanine aminotransferase). In this group of nine, the presence of tattoos had the highest and intravenous drug abuse the second highest correlation, also after the second interview. There is no vaccine available for the prevention of HCV infection, and prophylactic immunoglobulin therapy has no proven value for primary exposure.

Removal of a prosthetic modular femoral head is sometimes desirable during revision hip arthroplasty. A femoral head extractor was designed to heat and expand the prosthetic femoral head, apply a gentle distraction load, and remove the femoral head without injury to the femoral neck, taper, or bone—prosthesis interface. The device was used clinically in six hip revision cases. In five hips with cobalt—chrome heads and titanium alloy tapers, femoral heads were removed successfully; femoral fixation was maintained and femoral components were not visibly damaged. In the sixth case, the female portion of the taper junction was contained in a long femoral head sleeve. Heating the ball did not adequately expand the sleeve to allow easy ball removal.

We report two cases, each of which sustained two separate periarticular fractures from overzealous manipulation for knee contracture. The four fractures reported in this study involve one normal child sustaining asynchronous ipsilateral distal femoral and proximal tibial fractures and a child with the diagnosis of amyoplasia sustaining bilateral proximal tibial fractures. The child with knee contracture must be treated carefully and not exposed to overzealous physiotherapy or manipulation. The child who has developed a joint contracture secondary to lengthy immobilization may be at increased risk for periarticular fracture secondary to disuse osteopenia. The knee joint is at particular risk because of the long lever arm of the leg. These concerns should be conveyed to anyone involved in the patient's care, including the parents, therapists, nurses, and physicians. Passive range of motion in the child should never be painful. Normal children often can obtain maximal range of motion if left alone and not restricted.

Retrograde medullary screws were used in 26 patients with unstable pelvic ring injuries to stabilize the superior public ramus fractures. The posterior pelvic ring fractures and dislocations were fixed with iliosacral screws. The retrograde screws were inserted after closed manipulative reductions of the superior pubic ramus fractures in 15 patients and after open reduction in nine patients. We were unable to insert the screw in two patients due to anatomical variations. One screw was misplaced superior to the pubic ramus and noted only on the postoperative computed tomography scan. Another patient experienced symptomatic screw disengagement that required reoperation. All fractures healed and no infections developed. Blood loss was minimal for the percutaneous procedures. The technique provides stability to the anterior pelvic ring without the need for extensile surgical exposures. The complications of both anterior pelvic external fixation and plating are avoided, yet this technique has its own potential problems. The procedure is described in detail, and the early results and complications are documented in our first 26 patients.

We report four cases of acute midsubstance rupture of the patellar tendon that were treated with primary sur gical repair along with semitendinosus autograft aug mentation. The goal of this treatment was to allow im mediate mobilization of the knee with a single operative procedure. We also demonstrate a technique for de termining patellar position intraoperatively. Patients were tested for functional performance at an average final followup of 40 months (range, 20 to 66) including hamstring and quadriceps muscle strength evaluation, completion of a functional questionnaire, functional test performance, range of motion assessment, and patellar tendon length measurement. In evaluating the results, all cases were essentially identical to the nonoperated side, except one knee that had multiple associated liga ment injuries. The multitude of injuries to this knee are likely the cause of the discrepancy. Immediate midsub stance patellar tendon repair with semitendinosus aug mentation allowed immediate mobilization, which de creased the recovery period and improved the outcome of rehabilitation. Furthermore, a second surgery for hardware removal was not needed. These two factors— early and improved rehabilitation and the decreased chance of a second surgery—affect the cost of treat ment of this injury. All isolated patellar tendon injuries in the study had excellent function at followup. For these reasons, we recommend this procedure for acute pa tellar tendon ruptures.

We have reviewed our experience of four iatrogenic femoral neck fractures in 315 consecutive closed intramedullary nailings with the AO/ASIF universal femoral nail. The average neck-shaft angle in the bones that fractured was 139.3 degrees +/- 1.2 degrees SD (136 to 141); in the whole series the average neck-shaft angle was 125.3 degrees +/- 8.6 degrees and only 11 had angles of more than 135 degrees. The upper ends of the nails in the four which fractured were 17 mm, 5 mm, 3 mm, and 1 mm below the tip of the greater trochanter. In the seven patients with neck-shaft angles greater than 135 degrees but with no fracture, none of the nails had been inserted beyond the tip of the greater trochanter. We nailed six cadaver femora to simulate the forces produced by intramedullary nailing. Despite deep insertion, only one of the six sustained a neck fracture. This specimen had a radiographic neck-shaft angle of 140 degrees against an average of 127.3 degrees +/- 4.0 degrees for the other five. We believe that the medial prong of the AO insertion jig, with its medial overhang of 2 to 3 mm, may impinge on the superior aspect of a valgus femoral neck during final impaction, causing a neck fracture. This may be avoided by leaving the end of the nail above the tip of the trochanter in such cases.

Ehlers-Danlos syndrome (EDS) has been associated with irreparable arterial disruption, spontaneous and traumatic, necessitating amputation. Recurrent and chronic joint dislocation is a common component. Because of the very thin, hypermobile skin and "tissue paper scars," these patients would be expected to be poor candidates for the use of lower extremity prostheses. A review of the literature failed to show any reports of lower extremity prosthesis use in EDS patients or of recurrent and chronic joint dislocation treated by synthetic ligament reconstruction. The case of a 21-year-old woman is an example of both.

A greater understanding of the functional importance of the meniscus has prompted a more aggressive approach to conserving meniscal tissue. Multiple treatment options exist when dealing with a tear of the meniscus. As the popularity of bioabsorbable implants in the orthopaedic armamentarium grows, concern exists as to the potential associated complications. We describe a case of the failure of a bioabsorbable meniscal fixator appropriately applied to a posterior medial meniscal tear with an associated injury of the anterior cruciate ligament. Moreover, the concern of implant retention secondary to delayed degradation and resultant potential for articular cartilage damage was present. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 3 (March), 2001: pp E11–E11