Guidewire damage during cannulated screw fixation for slipped capital femoral epiphysis

Cannulated screw fixation of slipped capital femoral epiphysis is a standard procedure for the mild to moderately displaced slip. We report six cases in which the guidewire was damaged by a cannulated drill. In five the wire broke off within the femur. The broken wire was retrieved in two of the cases but not in the remaining three. The progress of all six patients was unaffected by this complication.     

Biomechanical testing of bioabsorbable cannulated screws for slipped capital femoral epiphysis fixation

This study compared cannulated 4.5-mm bioabsorbable screws made of self-reinforced poly-levolactic acid to cannulated 4.5-mm steel and titanium screws for resistance to shear stress and ability to generate compression in a polyurethane foam model of slipped capital femoral epiphysis fixation. The maximum shear stress resisted by the three screw types was similar (self-reinforced poly-levolactic acid 371 +/- 146 MPa, steel 442 +/- 43 MPa, and titanium 470 +/- 91 MPa). The maximum compression generated by both the self-reinforced poly-levolactic acid screw (68.5 +/- 3.3 N) and the steel screw (63.3 +/- 5.9 N) was greater than that for the titanium screw (3 +/- 1.4 N, P <.05). These data suggest cannulated self-reinforced poly-levolactic acid screws can be used in the treatment of slipped capital femoral epiphysis because of their sufficient biomechanical strength.     

Dyamic screw fixation for slipped capital femoral epiphysis. Treatment results

Slipped capital femoral epiphysis always requires surgical treatment. The operative technique depends on the degree of dislocation and the type of the slip. The goal of treatment is to achieve physeal stability until the epiphyseal plate closes without harming the further femoral growth. In situ fixation is generally recommended for slipped capital femoral epiphyses of a mild degree. For this purpose the technique of dynamic screw fixation (DSF) is applicable using a long cannulated screw with a short thread.DSF is easy to handle, provides sufficient long-term fixation of the epiphysis, does not promote premature closure of the epiphysis, and engenders few complications. Therefore, this technique is also applicable for the prophylactic treatment of the contralateral unaffected hip, which we always perform. Moreover, DSF can be used following gentle reduction of acute epiphysiolysis, if the amount of eventual residual dislocation does not exceed 30 degrees. We report our results with dynamic screw fixation of 29 slipped capital femoral epiphyses of a mild degree, and the prophylactic dynamic screw fixation of 34 unaffected hips. The fixation technique achieved a reliable stabilization with no visible growth disturbance of the femoral neck in all cases.     

Early reduction, arthrotomy, and cannulated screw fixation in unstable slipped capital femoral epiphysis treatment

Sixteen consecutive cases of unstable slipped capital femoral epiphysis treated with urgent reduction and pinning during a 7-year period are presented. In 2 of the 16 patients, avascular necrosis of the femoral head developed. Ten of the 16 patients were treated within 24 hours after the onset of acute symptoms by reduction, arthrotomy, and cannulated screw fixation of the hip using two screws. In none of these patients did avascular necrosis of the femoral head develop. Two patients required hardware removal for persistent pain, and one required a revision pinning after a nondisplaced femoral neck fracture. Chondrolysis did not develop in any patient, and no hip progressed after fixation. At last follow-up (mean 27 months after surgery), two patients walked with a moderate limp. Three reported persistent mild pain in the affected hip. Early reduction of unstable hips with arthrotomy and pinning using two cannulated screws to minimize the risk of avascular necrosis is recommended.     

Prospective evaluation of in situ screw fixation for stable slipped capital femoral epiphysis

Purpose:We aimed to determine which variables were associated with persistent symptoms or need for further surgery in patients treated with in situ fixation for stable slipped capital femoral epiphysis. We hypothesized that patients with greater proximal femoral deformity would require revision surgical intervention.Methods:We prospectively collected data on stable slipped capital femoral epiphysis patients who underwent in situ screw fixation at a single institution. Demographic and radiographic information, as well as patient-reported outcomes, were collected.Results:Forty-six patients (54 hips) with an average follow-up of 3.5 years (range: 2.0–8.5) and mean pre-op Southwick slip angle of 40.5° ± 19.4° were studied. We observed one complication following the index procedure (2%). Twelve hips (22%) went on to have a secondary procedure 2.7 ± 2.2 years after the index surgery. Severe slips were 14.8× more likely to undergo a secondary procedure than mild and moderate slips (p < 0.001). We found no correlation between slip severity and patient-reported outcomes (p > 0.6). Hips requiring a secondary procedure had significantly lower Hip disability and Osteoarthritis Outcome scores (76.8 ± 18.4) at final follow-up compared to hips that did not require additional surgery (86.8 ± 15.7) (p = 0.042).Conclusion:With minimum 2-year follow-up, 22% of patients required a secondary surgery. Patient-reported outcomes did not correlate with slip severity, but were found to be significantly higher in slipped capital femoral epiphysis patients that did not require a secondary procedure. Prophylactic treatment of all slip-related cam deformity was not found to be necessary in this prospective cohort. Patients with moderate-to-severe slips may require secondary surgery.Level of Evidence:Level II     

Complications at screw removal in slipped capital femoral epiphysis treated by cannulated titanium screws

Introduction: Various modes of fixation are proposed for the treatment of slips of the capital femoral epiphysis (SCFE). We describe our experience with the use and removal of a new, cannulated titanium screw (Asnis III, Stryker^®, Howmedica). Patients and methods: Single cannulated titanium screws had been inserted in 101 hips of 65 patients in the 3-year period from 2001 to 2003. These pins were used for in situ fixation of minor chronic slips in 41 patients and for prophylactic fixation on the contralateral side in patients with open physis in 60 patients. Results: The insertion of these screws was achieved without any real problem. The mean surgical time was 25 min (13–46 min). Problems came up when we started to remove the pins. Hardware retrieval was attempted in 27 patients with 43 pins. The mean surgical time for removal was double the average time of insertion with 51 min (26–107 min). The hexagonal Allen sockets proved to be too weak to overcome the necessary torque for loosening the pin from bone and applying the reverse-cutting-force, necessary to extract the pin. Eleven patients needed extensive chiselling. Two adolescents sustained a subtrochanteric fracture 5 and 7 weeks after hardware removal. Seven pins could not be totally removed. Conclusion: Due to the considerable disadvantages encountered in our series we conclude that Asnis III cannulated screws should be suspended from further use in SCFE.     

Intra-operative arthrography facilitates accurate screw fixation of a slipped capital femoral epiphysis

We report the case of a 13-year-old obese child presenting with bilateral stable slipped capital femoral epiphyses, which were managed by percutaneous single screw fixation in situ under image intensifier control using arthrography.     

Slip progression after in situ single screw fixation for stable slipped capital femoral epiphysis

The medical records and frog-leg lateral radiographs of 37 children with 46 stable slips treated with in situ single cannulated screw fixation at the Shriners Hospitals for Children, Lexington, from 1990 to 1998 were reviewed. The first postoperative frog-leg lateral radiograph was used to determine the head-shaft angle, the screw position, and the number of screw threads that engaged the epiphysis. The mean age at surgery was 12.3 years. The mean age when a frog-leg lateral radiograph first demonstrated physeal closure was 14.0 years. Nine slips (20%) demonstrated progression of more than 10 degrees from the first postoperative frog-leg lateral radiograph to the frog-leg lateral radiograph at first physeal closure. Slip progression appears inversely related to the number of screw threads engaging the epiphysis on the postoperative frog-leg lateral radiograph. The nine hips that progressed all had less than five screw threads engaging the epiphysis on the first postoperative frog-leg lateral radiograph. None of the 24 hips with five or more screw threads engaging the epiphysis on the first postoperative frog-leg lateral radiograph demonstrated progression. Slip progression was not related to screw position. Time to physeal closure was not related to screw position or the number of screw threads that engaged the epiphysis on the first postoperative frog-leg lateral radiograph. Screw advancement until five threads engage the epiphysis appears appropriate.     

Fixation with a single screw for slipped capital femoral epiphysis.

The effectiveness of a single 6.5 or seven-millimeter-diameter screw for the promotion of premature physeal closure and the provision of stability of a slipped capital femoral epiphysis was investigated. Physeal fusion was demonstrated in forty-nine (92 per cent) of fifty-three hips after fixation with a single screw. Premature fusion of the involved physis, compared with the uninvolved, contralateral physis, was documented (p less than 0.001). Epiphyseal stability, as measured by the lateral head-shaft angle, was maintained in all except one hip. An analysis of twenty-nine hips for which there was a complete set of radiographs, that were in patients who had no endocrine problems, and that were the first hips entered into the study when the patient had bilateral involvement, revealed an average time to closure of the physeal line of thirteen months. A longer time to physeal fusion was correlated with increasingly eccentric placement of the screw (r = 0.44, p = 0.016) and increasing severity of the slip (r = -0.536, p = 0.003). There was no correlation between the age at the time of the operation, race, or sex and the time to physeal fusion. Only one patient had penetration by a screw, and no chondrolysis, avascular necrosis, or other serious problems developed. Fixation with a single 6.5 or seven-millimeter-diameter screw provided adequate epiphyseal stability and promoted premature physeal fusion in our patients, while decreasing the rate of complications compared with that reported to be associated with fixation with multiple screws or pins.     

Continued growth of the hip after fixation of slipped capital femoral epiphysis using a single cannulated screw with a proximal threading

Background  

The most commonly used method for unstable slipped capital femoral epiphysis (SCFE) remains in situ fixation. Depending on the surgeon’s preference, screws or Kirschner wires are used for stabilizing the slipped upper femoral epiphysis. The purpose of this study was to evaluate the ability of a single cannulated screw with a proximal threading to ensure stabilization, growth, and remodeling of the slipped epiphysis.     

Valgus slipped capital femoral epiphysis

Abnormally high stresses involving the capital femoral physis were found in a series of valgus slipped capital femoral epiphysis cases. Using a single leg stance model we studied 10 hips in seven patients in which the epiphysis was lateral and posterior in relation to the femoral neck and calculated that shear stresses were high enough to be associated with failure of the physis. Valgus neck shaft angles and lateral tilt of the physes were seen in all cases.     

Familial slipped capital femoral epiphysis

In 50 consecutive cases of slipped capital femoral epiphysis (SCFE) from 49 families, the heredity was analyzed by radiographic examination of the first-degree relatives and by interview regarding the second-degree relatives. In four of the 49 families, SCFE was obvious in one or more first-degree relatives; and in another 13 families (14 relatives), radiographic signs of SCFE were found besides the primary case.

The familial accumulation was much higher than expected from incidence studies, indicating a hereditary factor in the etiology.     

Familial slipped capital femoral epiphysis

In 50 consecutive cases of slipped capital femoral epiphysis (SCFE) from 49 families, the heredity was analyzed by radiographic examination of the first-degree relatives and by interview regarding the second-degree relatives. In four of the 49 families, SCFE was obvious in one or more first-degree relatives; and in another 13 families (14 relatives), radiographic signs of SCFE were found besides the primary case. The familial accumulation was much higher than expected from incidence studies, indicating a hereditary factor in the etiology.     

Familial slipped capital femoral epiphysis

In 50 consecutive cases of slipped capital femoral epiphysis (SCFE) from 49 families, the heredity was analyzed by radiographic examination of the first-degree relatives and by interview regarding the second-degree relatives. In four of the 49 families, SCFE was obvious in one or more first-degree relatives; and in another 13 families (14 relatives), radiographic signs of SCFE were found besides the primary case.

The familial accumulation was much higher than expected from incidence studies, indicating a hereditary factor in the etiology.