Combined use of beta-tricalcium phosphate with different porosities can accelerate bone remodelling in open-wedge high tibial osteotomy.

Background/Objective: Beta-tricalcium phosphate (ß-TCP) is often used as a gap filler in open-wedge high tibial osteotomy (OWHTO). The aim of the present study was to investigate the effects of using ß-TCP with different porosities on bone remodelling after OWHTO.Methods: We evaluated 29 knees in 26 patients that underwent OWHTO using ß-TCP with porosities of 60% and 75% (combined group). A further 30 knees in 28 patients that underwent OWHTO using ß-TCP with 60% porosity alone were allocated as a control group. In the combined group, a ß-TCP block with 75% porosity was inserted into the gap at the cancellous bone site and a ß-TCP block with 60% porosity was inserted into the medial cortical bone side. In the control group, a ß-TCP block with 60% porosity was inserted into the osteotomy gap. The bone remodelling phases of the inserted ß-TCP blocks were evaluated on standard anteroposterior radiographs using the modified van Hemert classification at 3 and 6 months post-operatively. Results: The rate of satisfactory bone remodelling at the cancellous bone sites was 86.2% (25/29) in the combined group and 0% (0/30) in the control group at 3 months post-operatively (p<0.05), progressing to 96.6% (28/29) in the combined group and 20% (6/30) in the control group at 6 months post-operatively (p<0.05). Conclusion: The present study demonstrated that combined use of ß-TCP with high and low porosities can significantly enhance bone formation. The combined use of artificial bones with different porosities is useful for early bone remodelling in OWHTO.

Severe varus knees result in a high rate of undercorrection of lower limb alignment after opening wedge high tibial osteotomy.

PURPOSE: The purpose of this study was to clarify the indication for opening wedge high tibial osteotomy (OWHTO) in terms of lower limb alignment to achieve satisfactory clinical results. METHODS: Ninety-two patients (98 knees) with medial compartment knee osteoarthritis were investigated in this study. The average follow-up period was 34 months (range, 24-68 months). The average age of the patients at the time of surgery was 63 years (range, 41-77 years). RESULTS: The patients were divided into the following two groups according to the preoperative femorotibial angle (FTA) on anteroposterior full-length radiographs of the lower limbs while weight bearing: 29 knees with a preoperative FTA of ≥185° were defined as those with severe varus (S group), and the remaining 69 knees with a preoperative FTA of <185° were defined as those with mild varus (M group). Knees with a postoperative FTA of >175° were defined as undercorrected. The Lysholm score was used to assess the clinical results. The average postoperative FTA was 175.7° ± 4.1° in the S group and 174.6° ± 3.1° in the M group ( p = 0.013). Significantly, more undercorrected knees were observed in the S than M group ( p = 0.00035). The postoperative Lysholm score was 85.6 ± 8.5 in the S group and 88.5 ± 5.7 in the M group at the last follow-up ( p = 0.0033). CONCLUSION: Based on these results, we recommend that a preoperative FTA of <185° should be included as a criterion for OWHTO alone.

Patellar Dislocation in a Patient with Kabuki Syndrome with Severe Mental Retardation: A Case Report.

BACKGROUND: Kabuki syndrome is a rare congenital syndrome. Individuals with Kabuki syndrome have intellectual disabilities, often combined with skeletal anomalies and joint laxity. We herein report the first case of rehabilitation after reconstruction of the medial patellofemoral ligament in a patient with Kabuki syndrome. CASE: A 27-year-old woman with Kabuki syndrome and severe intellectual disability fell during an epileptic seizure. The right patella dislocated and then spontaneously reduced; similar episodes occurred repeatedly. Reconstruction of the medial patellofemoral ligament and lateral retinacular release were performed. Despite an intensive rehabilitation protocol, the patient's activities of daily living (ADL) did not quickly improve postoperatively because of her severe intellectual impairment and unwillingness to participate in rehabilitation exercises. About 3 months postoperatively, staff encouraged the patient to transfer from a wheelchair to a car, and she was able to get into the car with a little assistance. Subsequently, the patient's ADL gradually improved. By approximately 1 year postoperatively, the patient was able to ambulate independently for a few meters. DISCUSSION: The patient was thought to be interested in cars and in going for drives. Rehabilitation training for ADL improvement in patients with severe developmental disorders should include activities that the patients consider interesting.

Sports and Physical Activities of Elderly Patients with Medial Compartment Knee Osteoarthritis after High Tibial Osteotomy.

OBJECTIVE: We retrospectively investigated the preoperative and postoperative sports and physical activities (SPA) of elderly patients with medial compartment knee osteoarthritis who underwent opening-wedge high tibial osteotomy (OWHTO). METHODS: Fifty-six patients (62 knees) with medial compartment knee osteoarthritis were included in the study. The patients comprised 45 women and 11 men with a mean age at surgery of 71.6 years (range, 65-81 years). The mean follow-up period was 51±7 months. Patients who performed SPA to maintain their health for at least 30 min per session more than once a week were defined as SPA cases. The preoperative and postoperative ratios of SPA cases, the time to resuming or starting postoperative SPA, and the frequency of performing postoperative SPA were investigated. Clinical results were assessed using the Lysholm score. RESULTS: Fifteen patients (26.7%) performed SPA before OWHTO and 14 (25.0%) performed SPA after OWHTO (P=0.21). The mean time to resuming or starting SPA after surgery was 14.1±10.0 months, and the frequency of postoperative SPA sessions was 4.2±2.1 per week. The mean Lysholm score significantly improved from 60.8±8.9 preoperatively to 92.5±2.5 postoperatively (P<0.0001). CONCLUSION: The ratio of patients who performed SPA after OWHTO was still <30% , and it took a comparatively long time for patients to resume or start SPA after surgery.

Can squeaking with ceramic-on-ceramic hip articulations in total hip arthroplasty be avoided?

Squeaking is a recognized complication of total hip arthroplasty with ceramic on ceramic bearings but the etiology has not been well identified. We evaluated 183 hips in 148 patients who had undergone ceramic-on-ceramic noncemented total hip arthroplasties at one center between 1997-2007 by standardized telephone interviews and radiographic review. Audible squeaking was reported from 22 hips (12% of 183) of 19 patients. Prevalence of squeaking was associated with younger age; obesity; lateralized cup position; use of beta titanium alloy femoral components and shortened head length options; and higher reported activity level, greater pain, and decreased satisfaction at the time of the interview. Squeaking was described as having little personal significance by most patients. Squeaking might be preventable in part through medialization of the acetabular cup and avoidance of the use of shortened femoral necks.

Hip abductor muscle strength after total hip arthroplasty with short stems.

Excellent clinical results have been reported for total hip arthroplasty (THA) using a short stem. However, the range of variance in positioning of the stem has been reported to be wide. The authors hypothesized that the short stem position influences the femoral offset (FO) and hip abductor muscle strength (AMS) after surgery. The AMS was evaluated in 64 limbs in 32 patients who underwent unilateral THA using a short stem with a normal contralateral hip. The average time of AMS evaluation was 46.3 months postoperatively. The Harris Hip Score (HHS) was used for clinical evaluation. The ratio of the AMS on the reconstructed side to that on the contralateral side was calculated (strength ratio). The valgus angle (VA) of each stem and FO was measured on an anteroposterior hip radiograph. The FO ratio, as the normalized FO, was calculated. Linear regression analyses were performed to investigate the relationships among the VA, FO ratio and strength ratio. The average HHS improved from 57.7 points preoperatively to 94.6 points postoperatively. The VA negatively correlated with the FO ratio (r = -0.511, P = 0.028). The strength ratio negatively correlated with the VA (r = -0.505, P = 0.032) and positively correlated with the FO ratio (r = 0.479, P = 0.0056). The average postoperative HHS was generally satisfactory after THA using a short stem. A more valgus postoperative position of the short stem leads to reduced FO, which causes decreasing postoperative AMS after THA with a short stem.

Periacetabular osteotomy in patients fifty years of age or older: surgical technique.

BACKGROUND: Periacetabular osteotomy has been established as an effective treatment for early or mild osteoarthritis caused by developmental dysplasia of the hip. However, the optimal method of surgical reconstruction for older patients remains controversial. The purpose of this retrospective study was to evaluate the clinical and radiographic results of a curved periacetabular osteotomy for the treatment of developmental dysplasia of the hip in patients fifty years of age or older. METHODS: We evaluated forty-six consecutive hips in forty-two patients fifty years of age or older (the older group) who had developmental dysplasia of the hip and had undergone a curved periacetabular osteotomy between 1995 and 2006 with a minimum two-year follow-up period. The mean age was 54.6 years. We compared the clinical and radiographic results of this cohort with those of fifty hips in forty-four patients who were less than fifty years old (the younger group) and were managed with the same osteotomy. The mean age was 32.3 years. The patients were matched according to sex and Tönnis grade. Radiographic measurements included the center-edge angle, acetabular roof obliquity, acetabular head index, anterior center-edge angle, and head lateralization index. RESULTS: The mean Harris hip score improved from 69.6 points preoperatively to 90.9 points postoperatively in the older group and from 71.1 points preoperatively to 91.8 points postoperatively in the younger group. There were no significant differences in any of the radiographic measurements between the two groups preoperatively or postoperatively. The Tönnis grades improved in two hips and progressed in three hips in the older group and improved in three hips and progressed in three hips in the younger group. CONCLUSIONS: Satisfactory results can be obtained clinically and radiographically after curved periacetabular osteotomy in patients fifty years of age or older with Tönnis grade-1 or 2 osteoarthritis of the hip secondary to developmental dysplasia.

A periacetabular osteotomy for the treatment of severe dysplastic hips.

BACKGROUND: We believe a curved periacetabular osteotomy is indicated for treatment of severe dysplastic hips with center-edge angles less than 0°, classified as Severin Group IV-b. However, the lower limit of the center-edge angle in hips classified as Severin Group IV-b is not clearly defined to determine which patients should receive periacetabular osteotomy alone. QUESTIONS/PURPOSES: We retrospectively compared the results of curved periacetabular osteotomies performed for the treatment of severe (Severin Group IV-b: center-edge angle < 0°) and moderate (Severin Groups III and IV-a: center-edge angle ≥ 0°) dysplastic hips. We investigated the lower limit of the center-edge angle, which was corrected by a curved periacetabular osteotomy alone in Severin Group IV-b hips. PATIENTS AND METHODS: We divided 191 hips in 163 patients into moderate (147 hips) and severe (44 hips) dysplastic hip groups. Minimum followup was 2 years (mean, 70.9 and 70.6 months, respectively). Clinical evaluations were performed using the Harris hip score. Radiographic measurements included the center-edge angle, acetabular head index, acetabular roof obliquity, and head lateralization index. Complications were compared between the two groups. RESULTS: All clinical and radiographic postoperative parameters showed satisfactory improvement over the preoperative parameters in both groups. The postoperative acetabular roof obliquity and head lateralization index were equivalent between the two groups. Eleven hips deteriorated to end-stage osteoarthritis. No complications were specifically associated with the severe dysplastic hips. CONCLUSIONS: Curved periacetabular osteotomy alone for treatment of severe dysplastic hips with preoperative center-edge angles as low as -20° and classified as Severin Group IV-b restored weightbearing area and medialization.

Periacetabular osteotomy in patients fifty years of age or older.

BACKGROUND: Periacetabular osteotomy has been established as an effective treatment for early or mild osteoarthritis caused by developmental dysplasia of the hip. However, the optimal method of surgical reconstruction for older patients remains controversial. The purpose of this retrospective study was to evaluate the clinical and radiographic results of a curved periacetabular osteotomy for the treatment of developmental dysplasia of the hip in patients fifty years of age or older. METHODS: We evaluated forty-six consecutive hips in forty-two patients fifty years of age or older (the older group) who had developmental dysplasia of the hip and had undergone a curved periacetabular osteotomy between 1995 and 2006 with a minimum two-year follow-up period. The mean age was 54.6 years. We compared the clinical and radiographic results of this cohort with those of fifty hips in forty-four patients who were less than fifty years old (the younger group) and were managed with the same osteotomy. The mean age was 32.3 years. The patients were matched according to sex and Tönnis grade. Radiographic measurements included the center-edge angle, acetabular roof obliquity, acetabular head index, anterior center-edge angle, and head lateralization index. RESULTS: The mean Harris hip score improved from 69.6 points preoperatively to 90.9 points postoperatively in the older group and from 71.1 points preoperatively to 91.8 points postoperatively in the younger group. There were no significant differences in any of the radiographic measurements between the two groups preoperatively or postoperatively. The Tönnis grades improved in two hips and progressed in three hips in the older group and improved in three hips and progressed in three hips in the younger group. CONCLUSIONS: Satisfactory results can be obtained clinically and radiographically after curved periacetabular osteotomy in patients fifty years of age or older with Tönnis grade-1 or 2 osteoarthritis of the hip secondary to developmental dysplasia.

Hip abductor strengths after total hip arthroplasty via the lateral and posterolateral approaches.

A retrospective control study was carried out to compare the postoperative hip abductor strengths after primary total hip arthroplasties via the lateral (lateral group; 38 hips) and posterolateral (posterior group; 40 hips) approaches. At a minimum of 2 years after total hip arthroplasty, abductor muscle strength was evaluated qualitatively by the Trendelenburg test and quantitatively using a dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The Trendelenburg test was positive in 10 of 38 patients in the lateral group and in 11 of 40 patients in the posterior group. The average strength ratios of the lateral and posterior groups were 86.1% and 87.3%, respectively (P = .67). Strength ratio was positively correlated to femoral offset within both groups.

Ischemia of the lateral femoral cutaneous nerve during periacetabular osteotomy using Smith-Petersen approach.

BACKGROUND: Lateral femoral cutaneous nerve (LFCN) injury is a common complication in the Smith-Petersen approach to the hip. This complication may be induced by neural ischemia or direct trauma during the procedure. The purpose of this study was to investigate the relationship between the neural ischemia of LFCN and postoperative sensory disturbance. MATERIALS AND METHODS: Nineteen patients who underwent periacetabular osteotomy through the Smith-Petersen approach were investigated. To evaluate neural ischemia, we measured the blood flow of LFCN using a laser Doppler flowmetry. The measurements were performed before and after osteotomy at the point 1 cm distal from the lower border of the inguinal ligament. LFCN was retracted to the medial side during the procedure. There was no direct trauma to LFCN in all cases. Postoperative sensory disturbance was evaluated at 2 weeks, 3 months, and 1 year follow-up after surgery. RESULTS: After osteotomy, the blood flow of LFCN was decreased to 2.4 from 3.3 ml min(-1) 100 g(-1) when compared with that before osteotomy (P < 0.01). Postoperatively, 14 of 19 patients had sensory disturbance at 2 weeks, 8 of 19 patients at 3 months, and 2 of 19 patients at 1 year follow-up. The blood flows of both patients who had persistent symptoms over 1 year after surgery had been decreased by more than 50% during operation. CONCLUSIONS: Decrease of blood flow of LFCN by more than 50% seems to cause persistent symptoms after surgery through the Smith-Petersen approach even if direct trauma to the nerve is avoided. Excessive traction by retractors is thought to be the main cause of blood flow reduction.

Prevalence of femoroacetabular impingement in Asian patients with osteoarthritis of the hip.

Although femoroacetabular impingement (FAI) has recently been considered to be one of the causes of osteoarthritis (OA) of the hip, the exact pathogeneses and incidence of FAI and primary OA are unknown. The purposes of this study were to investigate the causes of hip OA in Japan and to clarify the prevalence of FAI in patients with hip OA. We retrospectively investigated 817 consecutive patients (946 hips) who underwent primary surgery with the diagnosis of OA of the hip. Clinical recordings and preoperative radiographs were evaluated to determine the cause of OA. There were 17 hips who had primary OA, of which six hips were determined to be FAI positive. The remaining 11 cases without FAI had primary OA of unknown aetiology. Our study has revealed that most hip OA cases were caused by developmental dysplasia of the hip. We only found a few cases (0.6%) with FAI in Japan.

Effect of superior placement of the hip center on abductor muscle strength in total hip arthroplasty.

We evaluated 100 limbs in 50 patients who had undergone unilateral primary total hip arthroplasty with a normal contralateral hip. The 50 patients were divided into 2 groups by postoperative acetabular cup position, specifically by inferior and superior placement (inferior and superior groups). Hip abductor muscle strength was evaluated qualitatively by the modified Trendelenburg test and quantitatively by handheld dynamometer. The ratio of normalized strength of the reconstruction side to that of the nonoperated side was calculated (strength ratio). The modified Trendelenburg test was positive in 5 of 23 patients in the inferior group and 11 of 27 in the superior group (P < .05). The strength ratio of the superior group was decreased by 7.7% in comparison with that of the inferior group (P < .01).

Postoperative acetabular retroversion causes posterior osteoarthritis of the hip.

We retrospectively reviewed 68 hips in 62 patients with acetabular dysplasia who underwent curved periacetabular osteotomy. Among the 68 hips, 33 had acetabular retroversion (retroversion group) and 35 had anteversion (control group) preoperatively. All hips were evaluated according to the Harris hip score. Radiographic evaluations of acetabular retroversion and posterior wall deficiency were based on the cross-over sign and posterior wall sign, respectively. The clinical scores of the two groups at the final follow-up were similar. In the retroversion group, 12 hips had anteverted acetabulum postoperatively. The posterior wall sign disappeared in these hips, but remained in 21 hips with retroverted acetabulum postoperatively. Among the 21 hips with retroverted acetabulum, posterior osteoarthritis of the hip developed postoperatively in five hips. When performing corrective osteotomy for a dysplastic hip with acetabular retroversion, it is important to correct the acetabular retroversion to prevent posterior osteoarthritis of the hip due to posterior wall deficiency.

Periacetabular osteotomy for the treatment of dysplastic hip with Perthes-like deformities.

We retrospectively evaluated 17 hips in 16 patients who underwent a periacetabular osteotomy for the treatment of dysplastic hip with Perthes-like deformities. These residual deformities were graded using the Stulberg classification system. There were three class II hips, 11 class III hips and three class IV hips preoperatively. The average age of the patients at surgery was 36.9 years and the average follow-up was 6.6 years. The average Harris hip score significantly improved from the preoperative value of 68.2 points to 91.1 points postoperatively. The average postoperative range of motion in all directions did not change significantly from the preoperative value. The average postoperative Harris hip score of class IV hips was smaller than that of the class II or class III hips. The standard radiographic evaluations also showed significant improvements postoperatively. Periacetabular osteotomy without combined femoral osteotomies, as a treatment for patients with Perthes-like deformities, produced good clinical and radiographic results.

Comparison of skin blood flow between mini- and standard-incision approaches during total hip arthroplasty.

Twenty patients who underwent total hip arthroplasty were randomly allocated to have surgery through a mini incision of < or = 8 cm (mini-incision surgery [MIS] group, n = 10) or a standard incision of 14 cm (standard group, n = 10). A laser Doppler flowmeter was used to measure the intraoperative blood flow of the skin. The measurements were performed at 2 regions, specifically, anterior and posterior regions across the middle points of skin incision. The measurements were taken before making the incision and after implantation. As a control, the skin blood flow over the anterior superior iliac spine was measured. After implantation, mean skin blood flows at both regions in the MIS group were significantly decreased by 32% and 33%. However, the corresponding flows in standard group and control regions were constant during operation.