Fixation with poly-L-lactic acid screws in hip osteotomy: 68 hips followed for 18-46 months

This study evaluated 68 consecutive hip osteotomies in 61 patients using absorbable poly-L-lactic acid screws for fixation. 47 hips underwent a rotational acetabular osteotomy, 17 hips Chiari's pelvic osteotomy, and 4 hips transtrochanteric rotational osteotomy. Cortical screws were used to transfix the osteotomized acetabulum, and cancellous screws to reattach the intraoperatively osteotomized greater trochanter. The average age at surgery was 35 (12-49) years. The mean duration of follow-up was 32 (18-46) months. All the osteotomized acetabulums united well, but 4 of 54 trochanteric osteotomies failed to unite.     

Radiographic and magnetic resonance imaging findings of polylevolactic acid screws after rotational acetabular osteotomy

Introduction Biodegradable polylevolactic acid implants have become more commonly used for the treatment of fractures and osteotomies over the past few years. In the present study, the biocompatibility and degradation of polylevolactide screws used for rotational acetabular osteotomy were assessed on the basis of radiographic and MRI findings.Materials and methods Forty-nine hips of 47 patients were analyzed for this study. The average age of the patients at the time of surgery was 38.0 years (range 18–62 years). The original diagnosis was osteoarthritis in 43 hips and osteonecrosis in 6 hips. The mean duration of follow-up was 2.8 years (range 1.5–5.5 years). Anteroposterior radiographs obtained at 1 week, 6 months, 1 year after the operation, as well as the most recent radiographs, were used to assess bony union, the radiolucent tract of each screw, and the sclerotic rim around each screw. Fifteen patients were chosen randomly to undergo MRI.Results Union of the osteotomized surfaces occurred in all patients within 6 months of surgery. Radiographs showed no osteolysis, no formation of bone cysts, and no displacement of the osteotomized acetabulum in any of the 49 hips. None of the patients was found to have any complications caused by problems with the biocompatibility of the implants. At the final postoperative examination, a central radiolucent tract and a sclerotic rim around the screws were seen in 34/49 hips (69%) and 23/49 hips (47%), respectively. On MRI findings, we were able to detect significant resorption of the screws in two patients after 1.2 and 1.7 years of follow-up. Though localized low-intensity areas on T1-weighted images and high-intensity areas on T2-weighted images were observed at the top of the screws in 5 patients, there was no development of pain, tenderness, or a sinus during the follow-up period.Conclusion Although absorption of polylevolactic acid screws did not occur in a large majority of cases, rotational acetabular osteotomy appears to be a good indication for the use of polylevolactic acid screws.     

Use of a screw and plate system for a transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head

Background We originally used two or three large cancellous screws for a transtrochanteric rotational osteotomy for osteonecrosis. Since January 2002, a screw and plate system (K-MAX Adjustable Angle Hip Screw) has been used to obtain more rigid fixation at the site of osteotomies. We investigated the clinical and radiological results of a transtrochanteric anterior rotational osteotomy. Methods Between January 2000 and December 2001, a transtrochanteric anterior rotational osteotomy with large cancellous screws was performed in 25 hips of 22 patients, and between January 2002 and March 2005, the K-MAX Adjustable Angle Hip Screw was used in 44 hips of 40 patients for treatment of osteonecrosis of the femoral head. Japanese Orthopaedic Association (JOA) score, postoperative management, and radiographic appearances were investigated. Results The mean preoperative JOA score was 60.8 ± 12.1 points in the large cancellous screw group and 61.5 ± 14.4 points in the K-MAX Adjustable Angle Hip Screw group. This improved to 86.1 ± 13.3 points in the large cancellous screw group and 88.7 ± 6.6 points in the K-MAX Adjustable Angle Hip Screw group at the final follow-up. Intentional varus angulations were obtained in 15 of 25 hips in the large cancellous screw group and in 36 of 44 hips in the K-MAX Adjustable Angle Hip Screw group. Altogether, 23 of 25 (92.0%) cases with large cancellous screws started partial weight-bearing 7 weeks after the operation, and 43 of 44 (97.7%) cases with the K-MAX Adjustable Angle Hip Screw started 5 weeks after the operation. Conclusions The K-MAX Adjustable Angle Hip Screw produced clinical results similar to those with the large cancellous screws. In addition, partial weight-bearing could be started 2 weeks earlier after a transtrochanteric anterior rotational osteotomy with the K-MAX Adjustable Angle Hip Screw.     

Polylactide screws in acetabular osteotomy: 28 dysplastic hips followed for 1 year

Absorbable polylactide screws were used for internal fixation of rotational acetabular osteotomy (RAO) in 28 dysplastic hips. No cast was used and the patients were allowed to walk with partial weight bearing 1 month after surgery. Clinical and radiographic results were evaluated after 14 (6-24) months. Union occurred in all cases within 4 months without displacement of the osteotomy. No foreign-body inflammatory reaction on radiographs was observed, nor were there any local reactions, such as redness or swelling. Polylactide screws seem to provide sufficient strength for the internal fixation of RAO. Further observation is necessary to identify any late foreign body reaction.     

Ectopic bone formation around the poly-<Emphasis Type="SmallCaps">l</Emphasis>-lactide screw head in rotational acetabular osteotomy for hip dysplasia

Ectopic bone formation around the poly-l-lactide (PLLA) screw head in eccentric rotational acetabular osteotomy for hip dysplasia was investigated. A total of 174 hips in 165 patients with hip dysplasia were consecutively treated with eccentric rotational acetabular osteotomy. Average age at the time of operation was 37 years. Acetabular fragments of 123 patients (132 hips) were fixed by Kirschner wires (K-wire group), and 42 hips in 42 patients were fixed with PLLA screws (PLLA group). There was no statistically significant difference between the backgrounds of the two groups. All patients were evaluated clinically and radiologically. In the K-wire group, ectopic bone formation of class 2 was observed in only 1 hip. In the PLLA group, ectopic bone formation of class 3 in 1 hip and class 2 in 3 hips was observed around the screw head 3 months postoperatively, and all hips but 1 showed class 2 at final follow-up. One hip with class 3 at 1 year developed marked reduction of range of motion, and this patient complained of moderate hip pain and stiffness. PLLA screws significantly enhanced ectopic bone formation around the screw head in eccentric rotational acetabular osteotomy.     

Transtrochanteric Posterior Rotational Osteotomy for Osteonecrosis

When osteonecrosis is located in the mid- to posterior region, we generally perform a transtrochanteric posterior rotational osteotomy. We retrospectively reviewed the clinical and radiographic results in 47 consecutive patients (51 hips) in whom we performed posterior rotational osteotomies. The average age was 37 years at the time of surgery. There were 30 male and 17 female patients. Thirty-six hips were ARCO Stage III, and 15 were Stage IV. Conversion to THA was defined as the failure end point. Three patients died and one was lost to followup. We were therefore able to follow 43 patients (46 of the 51 hips, or 90%) a minimum of 1.2 years (average, 12 years; range, 1.2-21 years). We used the Harris hip score for preoperative and most recent followup. The average preoperative Harris hip score of 52 points improved to an average of 84 at the latest followup. Radiographically, the osteonecrosis in 30 hips (65%) had no progressive collapse, and 13 (28%) showed osteoarthritic changes, but no patients underwent THA. A posterior rotational osteotomy appears useful for patients with extensive necrosis and advanced collapse.     

A computer simulation of rotational acetabular osteotomy for dysplastic hip joint: does the optimal transposition of the acetabular fragment exist?

For young patients who have early signs of coxarthrosis resulting from acetabular dysplasia, periacetabular osteotomies for correcting abnormal stress distribution can be useful for preventing the progression of the disease. However, it is difficult to confirm the optimal transposition of the osteotomized acetabular fragment. To deal with this problem, we devised a computer program to support preoperative planning. Hip images obtained by computed tomography were loaded into our program, and a three-dimensional voxel model was created. Then, osteotomy was simulated and the pressure distribution was analyzed with a rigid-body spring analysis (computational nonlinear mechanical analysis). The three-dimensional pressure distributions in seven dysplastic hips were evaluated before and after virtual rotational acetabular osteotomy. A peak pressure was calculated for every 5° of rotation of the acetabular fragment. The peak pressure decreased gradually and increased again afterward, indicating the optimal transposition of the acetabular fragment. The postoperative peak pressure decreased to about 40% in the most improved case. This program allows the hip joint mechanics to be evaluated easily so that the advantages and disadvantages of various surgical methods can be examined biomechanically prior to surgery.     

Comparison of two methods of screw fixation in periacetabular osteotomy

The optimal method of fixation during periacetabular osteotomy is unknown. Periacetabular osteotomies were created on both sides of six whole pelves from fresh cadavers and were fixed randomly either with three long 4.5-mm cortical screws from the iliac crest to the osteotomized fragment (iliac fixation) or with two such screws supplemented by a transverse screw from the acetabular segment to the ilium (transverse fixation). Pelvis loading in simulated push-off phase of the gait cycle was accomplished using a custom-made fixture. Linear potentiometers measured displacements at the pubic and ischial osteotomies. Fracture site stiffness was calculated from actuator force and pubic osteotomy displacement data. Displacement of the pubic osteotomy averaged 12.8 mm in the iliac fixation group and average 12.45 mm in the transverse group fixation. The ultimate loads beyond which catastrophic failure occurred were measured from 531.27 N to 1103.3 N (mean, 741.5 N) and 660.9 N to 1273.9 N (mean, 930.8 N), respectively. Effective stiffness ranged from 38.9 N/mm to 117 N/mm in the iliac fixation group (mean, 77.8 N/mm), and from 99 N/mm to 315 N/mm in the transverse construct (mean, 182 N/mm). Although the transverse screw provided statistically significantly greater local stiffness to the periacetabular construct fixation, neither type of fixation provided enough stability to allow immediate weightbearing after periacetabular osteotomy.     

The displacement of the femoral head by rotational acetabular osteotomy. A radiographic study of 97 subluxated hips.

To determine the limits of medial and inferior displacement of the subluxated femoral head by rotational acetabular osteotomy, we studied the acetabular coverage and position of the femoral head radiographically before and after surgery in 97 hips. The median age of the patients at the time of surgery was 33 (18-54) years. The position of the femoral head was represented by its center and medial and upper borders. The average increase and decrease in the CE and the AC angle were 39 degrees and 27 degrees, respectively. The average medial displacement of the head was 8 (-12 to +19) mm measured from its center, and 7 (-10 to +21) mm measured from its medial border. The average inferior displacement was 5 (-6 to +19) mm from its center and 4 (-10 to +15) mm from the upper border. These results indicate that concentric reduction by rotational acetabular osteotomy is limited and that medial displacement of the subluxated femoral head is within similar ranges obtained by other conventional pelvic osteotomies.     

Retroversion of the acetabular dome after Salter and triple pelvic osteotomy for congenital dislocation of the hip

Retroversion of the acetabular dome has been associated with hip pain and osteoarthritis in several studies. Nevertheless, this acetabular alignment received little attention when studying the radiological outcome of pelvic osteotomies in childhood. We therefore reviewed the charts and X-rays of 73 patients with congenital dislocations, who underwent 97 pelvic osteotomies in childhood. We focussed our attention on anterior overcoverage or retroversion of the acetabular dome, respectively. Eighty-six Salter and 11 LeCoeur osteotomies were performed on patients with a mean age of 4.8 years. The mean age at last X-ray documentation was 16.5 years. The version of the acetabular dome was estimated qualitatively from the relationship of the anterior and posterior border to each other and measured semiquantitatively using templates developed by Hefti. According to Lequesne's criteria 94% of the hips were normal or borderline at maturity. A retroverted acetabular dome was present in 27% and averaged -15 degrees. It was more frequent (60% versus 24%) and more pronounced (-16 degrees versus +5 degrees) after Le Coeur's than after Salter's osteotomy and in the residually dysplastic hips (83% versus 22%; -15 degrees versus +3 degrees). It is suggested that anterior overcoverage of the femoral head results from ignorance, when choosing the type and performing the pelvic osteotomy, of where coverage needs to be improved in an individual hip. We question the long-term outcome of these hips because such rotational misalignment has been suggested to be associated with early hip pain and osteoarthritis. In order to avoid such misalignment, preoperative evaluation of where coverage needs to be improved in an individual hip and efforts for better intraoperative control of acetabular reorientation should be made.     

Rotational acetabular osteotomy for acetabular dysplasia. A follow-up for more than ten years

Between 1986 and 1990, we carried out 55 rotational acetabular osteotomies in 54 patients with acetabular dysplasia. Five hips were lost to follow-up. Of the 50 remaining, the degenerative changes were classified according to the criteria of T?nnis as grade 0 in 23, grade 1 in 16 and grade 2 in 11. The mean age of the three men and 46 women at the time of operation was 31.8 years (13 to 53). The mean follow-up was 137 months (120 to 174). At the most recent follow-up, 48 patients had satisfactory relief from pain. There was a slight decrease in the range of movement, particularly of flexion, in 18 hips. Radiologically, all osteotomies had united satisfactorily. There was radiological evidence of improvement in degenerative changes in 13 hips (5 grade 1 and 8 grade 2). Ten deteriorated (5 grade 0, 3 grade 1, and 2 grade 2) and one required total hip arthroplasty ten years after osteotomy. The osteoarthritis in the two hips with an associated valgus osteotomy progressed. The changes in radiological indices such as the centre-edge angle, acetabular femoral head index, acetabular root obliquity and horizontal or vertical displacement of the femoral head showed no statistical difference (unpaired Student's t-test) between the patients with radiological progression and those with and without improvement.     

Original methods to move femoral head medially and caudally after rotational acetabular osteotomy: especially to use ceramic spacer

The operative procedures chosen to treat arthrosis in patients with severe acetabular dysplasia vary among orthopaedic surgeons, particularly in younger patients. We operated on 450 hips with acetabular dysplasia by using the rotational acetabular osteotomy (RAO) method of Ninomiya and Tagawa by Ninomiya (Clin Orthop 247:127–137, 1989). In this report, we describe our technique of performing RAO with hydroxyapatite tricalcium phosphate-composite (HAP-TCP) blocks to achieve good acetabular coverage and the results of this procedure in 16 hips with severe dysplasia, including nine with advanced arthrosis. Adequate coverage of the osteotomized acetabulum was maintained and symptoms, especially pain, showed marked improvement at the latest follow up.     

Mechanical comparison of fixation techniques for the tibial tubercle osteotomy

Tibial tubercle osteotomies currently are used as an exposure technique for revision total knee arthroplasty and for distal patellofemoral realignment. A review of the literature reveals no biomechanical studies that evaluate methods of osteotomy fixation in terms of static strength. This study evaluates the fixation strength of common techniques used to repair tibial tubercle osteotomies. Bevel and stepcut tibial tubercle osteotomies were created in 36 anatomic specimen knees and were repaired with either two 4.5-mm cortical screws or 18-gauge stainless steel cerclage wire. The failure load for the bevelcut osteotomies repaired with two-screws was 1,654 +/- 359 N; for the bevelcut osteotomies repaired with three cerclage wires, 622 +/- 283 N; for the stepcut osteotomies repaired with three cerclage wires, was 984 +/- 441 N; and for the stepcut osteotomy repaired with four cerclage wires, 1,099 +/- 632 N. This study shows that two bicortical screws provide the greatest static fixation strength for repairing tibial tubercle osteotomies. When repairing tibial tubercle osteotomies for distal patellofemoral realignment, screw fixation would provide the most reliable fixation. However, the placement of screws around the stem of a revision arthroplasty tibial component is difficult. Cerclage wires are easier to place and provide solid static fixation, especially with the addition of a proximal stepcut osteotomy.     

Posterior rotational osteotomy for the treatment of femoral head osteonecrosis

Posterior rotational osteotomy in 46 hips of 39 patients with femoral head osteonecrosis was reviewed radiographically and clinically after 2-12 years of follow-up (mean 5 years). The age of the patients at the time of surgery ranged from 18 to 60 years, with a mean of 35 years. There were 18 women and 21 men. The cause of the osteonecrosis was steroid administration in 14, alcohol abuse in 5, trauma in 16, and no apparent risk factor in 4. According to the Ficat staging system, 2 hips were stage II, 30 hips III, and 14 hips stage IV. All hips had an extensive lesion. Forty-one hips showed less than 1/3 noncollapsed posterior living area, which was a contraindication for traditional anterior rotational osteotomy. The posterior rotational angle was 60-180 deg with an mean of 127 deg. Recollapse of the final follow-up anteroposterior radiograph was prevented in 36 hips (78%). Progressive joint space narrowing was found in 12 hips (26%). Of these hips, 9 suffered recollapse, while the remaining 3 hips did not. Clinically, 32 hips (70%) showed excellent or good results (both hips in stage II, 23 of 30 hips in stage III, 7 of 14 hips in stage IV. A fair or poor result was seen in 14 hips (30%)). These results suggest that posterior rotational osteotomy is effective in delaying the progression of degeneration for large necrotic lesions, especially in young patients. Extent of rotation is limited to 150 deg because of limitations of bone quality. The indications should be refined further, and longer term follow-up is necessary.     

Late-diagnosed DDH: A prospective 11-year follow-up of 71 consecutive patients (75 hips)

I have prospectively studied 71 consecutive patients (75 hips) with late-diagnosed DDH (developmental dysplasia of the hip) treated uniformly with special reference to the development of the femoral head and the acetabulum. The age at the start of treatment was 10 (2-64) months. The follow-up time was 11 (6-18) years. After tenotomy and traction, closed reduction failed in 7 hips. These cases were treated by open reduction with or without Salter innominate osteotomy - in 2 hips femoral osteotomy was also done (shortening, varus and derotation). 1 hip subluxated and 1 re-dislocated after closed reduction. Avascular necrosis occurred in 4 hips and additional surgery was required in 12 hips - 11 Salter osteotomies, 1 varus femoral osteotomy. In the first year after reduction, the acetabular angle improved rapidly - faster in the younger children. When treatment started between 12 and 22 months, the improvement was slower and the final outcome more unpredictable. The femoral head continued to grow irrespective of the age at reduction and became normal in almost all cases. Salter's innominate osteotomy stabilized hips after open reduction and gave excellent results in cases with an increasing acetabular angle. At the last re-examination, all but 2 patients were asymptomatic. Radiographically, 65 hips were rated Severin group I, 9 group II and 1 group III.     

Late-diagnosed DDH: A prospective 11-year follow-up of 71 consecutive patients (75 hips)

I have prospectively studied 71 consecutive patients (75 hips) with late-diagnosed DDH (developmental dysplasia of the hip) treated uniformly with special reference to the development of the femoral head and the acetabulum. The age at the start of treatment was 10 (2-64) months. The follow-up time was 11 (6-18) years. After tenotomy and traction, closed reduction failed in 7 hips. These cases were treated by open reduction with or without Salter innominate osteotomy - in 2 hips femoral osteotomy was also done (shortening, varus and derotation). 1 hip subluxated and 1 re-dislocated after closed reduction. Avascular necrosis occurred in 4 hips and additional surgery was required in 12 hips - 11 Salter osteotomies, 1 varus femoral osteotomy. In the first year after reduction, the acetabular angle improved rapidly - faster in the younger children. When treatment started between 12 and 22 months, the improvement was slower and the final outcome more unpredictable. The femoral head continued to grow irrespective of the age at reduction and became normal in almost all cases. Salter's innominate osteotomy stabilized hips after open reduction and gave excellent results in cases with an increasing acetabular angle. At the last re-examination, all but 2 patients were asymptomatic. Radiographically, 65 hips were rated Severin group I, 9 group II and 1 group III.     

Long-term results after open reduction of developmental hip dislocation by an anterior approach lateral and medial of the iliopsoas muscle

The technique of and especially the approach to open reduction of developmental dislocation of the hip are still a matter of discussion. The anterior approach, first lateral and then medial to the iliopsoas muscle, was described by Tonnis in 1978. A follow-up investigation to adulthood has now been performed. Eighty-seven children (118 hips) out of 105 children (83%) who underwent open reduction of developmental dislocation of the hip before the age of 4 years were reinvestigated 10-21 years after the operation. An anterior approach first lateral, then medial to the iliopsoas muscle was chosen, because this offers the best access to the joint. Additional operations including transiliac osteotomy for acetabuloplasty, shortening osteotomy, and femoral osteotomies were performed as necessary. In 92 (78%) of the 118 hips studied the CE angle exceeded 25 degrees and in 98 hips (83%) the VCA angle exceeded 25 degrees. Critical CE angles between 20 and 25 degrees were found in 14% of the hips, and critical VCA angles in 4%. Residual dysplasia (<20 degrees) was found in 8 and 13% of the hips, respectively. Avascular necrosis according to Hirohashi was observed after operation in grade 1 in 5.9% and grade 2 in 1.7%. No necrosis was found following shortening osteotomy of the proximal femur. The anterior approach, first lateral, then medial to the iliopsoas muscle, offers an optimal access to the medial parts of the joint with control of reduction, protects the vasculature of the femoral neck, and allows simultaneous postero-lateral capsulorrhaphy and pelvic osteotomies.     

Experiences with the Pauwels osteotomy and its improvement in the last 20 years]

Intertrochanteric osteotomies (Pauwels) were performed in 203 hips. Their average age at operation was 41 years (range 15 to 66 years). Average follow-up was 16 years and 5 months. 78 of 203 hips had been undergone varus osteotomies (P1) and valgus osteotomies (P2) were in 125 hips. All the hips were evaluated clinically and radiologically. 140 hips (69%) had no pain. 132 hips (65%) showed no arthritic changes. In summary, we feel that Pauwels' osteotomy is a reliable method in the treatment of the young and middle aged patient.     

Extended trochanteric osteotomy via the direct lateral approach in revision hip arthroplasty

A review of the results of the extended trochanteric osteotomy through a modified direct lateral approach in revision total hip arthroplasty was done. We reviewed 44 patients (45 procedures) at a minimum of 2 years followup (mean, 3.8 years; range, 2.1-7.2 years). There were 26 men and 18 women with a mean age at the time of surgery of 70.8 years (range, 36.9-90.4 years). Indications for use of the trochanteric osteotomy included facilitation of cement removal (25 procedures), proximal femoral varus deformity (14 procedures), trochanteric malposition (five procedures), and previous trochanteric osteotomies with significant bony overgrowth (three procedures). The mean length of the osteotomy was 133.9 mm. The mean migration of the osteotomized fragment was 2.1 mm (range, 0-20 mm) with significantly more proximal migration seen with the use of cerclage wires when compared with cables. There were two cases of trochanteric escape, for which the patients required repeat open reduction internal fixation. There were two late fractures of the greater trochanter. One femoral component had early subsidence for which the patient required re-revision with a further extended trochanteric osteotomy. The mean time to union of the remaining 40 hips was 10.3 months (range, 6-24 months). There only was one dislocation postoperatively. The extended trochanteric osteotomy through the modified direct lateral approach in revision total hip arthroplasty is a reproducible and reliable technique with a lower dislocation rate but a higher incidence of trochanteric fracture and escape than previously described with its use in the posterior approach.     

改良髋臼周围截骨术治疗儿童发育性髋关节脱位

目的 :探讨改良髋臼周围截骨术式治疗儿童发育性髋关节脱位。方法 :采用髋臼周围截骨术联合髋臼加盖术 ,截骨端以楔形骨块充分植骨治疗儿童发育性髋关节脱位 3 7例 47髋。结果 :随访 3 0例 ,3 8髋。随访 1 5～ 5年 ,平均 3 2年。按周永德评定标准 ,优 3 1髋 ,良 6髋 ,可 1髋。结论 :改良髋臼周围截骨术是治疗发育性髋关节脱位较理想的方法