Assessing Foot Loads in Continuous Passive Motion (CPM) and Active Knee Joint Motion Devices.

BACKGROUND: Continuous passive motion (CPM) and active knee joint motion devices are commonly applied after various surgical procedures. Despite the growing use of active motion devices, there is a paucity of data comparing plantar loads between the different mobilization techniques. The aim of this study was to investigate foot loads during knee joint mobilization in continuous passive and active knee joint motion devices and to compare this data to the physiological load of full weight-bearing. PATIENTS/MATERIAL AND METHODS: Fifteen healthy participants (7 women and 8 men, 25 ±â€Š3 years, 66 ±â€Š6 kg, 175 ±â€Š10 cm, BMI 21.9 ±â€Š2) were recruited. Plantar loads were measured via dynamic pedobarography using a continuous passive motion device (ARTROMOT-K1, ORMED GmbH, Freiburg, Germany) and an active motion device (CAMOped, OPED AG, Cham, Switzerland), each with a restricted range of motion of 0-0-90° (ex/flex) and free ROM for the knee joint. For the active motion device, cycles were performed at four different resistance levels (0-III). Data were assessed using the pedar® X system (Novel Inc., Munich, Germany), which monitors loads from the foot-sole interface. Force values were compared between motion devices and normal gait, which served as the reference for conditions of full weight-bearing. P-values of < 0.05 were considered statistically significant. RESULTS: Normal gait revealed peak forces of 694 ±â€Š96 N, defined as 100 %. The CPM device produced plantar forces of less than 1.5 N. Using the active motion device in the setting of 0-0-90° produced foot loads of < 1.5 N (resistance 0-II) and 3.4 ±â€Š9.3 N with a resistance of III (p < 0.001). Conditions of free ROM resulted in foot loads of 4.5 ±â€Š4.5 N (resistance 0), 7.7 ± 10.7 N (resistance I), 6.7 ±â€Š10.4 (resistance II) and 6.7 ±â€Š6.9 N with a resistance of III (p < 0.001), corresponding to 0.6 %, 1.1 %, 1.0 % and 1.0 % of full weight-bearing, respectively. CONCLUSION: Motion exercises of the knee joint can be performed both with passive and active devices in accordance with strict weight-bearing restrictions, which are often recommended by surgeons. Also, active motion devices can be used when the ankle joint or foot have to be offloaded. Further studies assessing intraarticular joint load conditions have to be performed to confirm the findings obtained in this study.

A cross-sectional study on foot loading patterns in elite soccer players of different ages.

BACKGROUND: Alterations in plantar loading patterns are risk factors for stress injuries of the lower limb, particularly of the foot and ankle. Epidemiological studies have revealed a higher incidence of soccer-related stress fractures of the fifth metatarsal (MT V) in younger athletes than in their adult counterparts. OBJECTIVE: The aim of the present study was to assess the plantar pressure distributions of members of four high-level soccer teams of different age groups to identify age-related differences in loading patterns. METHODS: A total of 65 elite soccer players were included in the study. Data were computed with sensor-loaded insoles (pedar® X system, novel Inc., Munich, Germany) while the players ran in soccer shoes. Plantar pressures for nine defined regions on the preferred and nonpreferred foot were analyzed. RESULTS: The participants consisted of 17 elite male soccer professionals from the first national league (mean 23 years, height 184 cm, weight 81 kg), 14 players from the under-21 squad (U21, 20 years, 180 cm, 75 kg), 15 players from the U17 squad (16 years, 176 cm, 69 kg) and 19 players from the U16 squad (15 years, 179 cm, 70 kg). We detected statistically significantly elevated peak pressures on the lateral aspects of the nonpreferred foot compared with the preferred foot in the U16 and U17 players, corresponding to a relative increase by 29% (p= 0.044) in the lateral midfoot, a relative increase by 24% (p= 0.031) in MT heads 4-5 in the U16 players and a difference of 18% (p= 0.049) in the lateral midfoot in the U17 players. In contrast, the U21 and adult professional players displayed symmetric plantar pressure distributions in all foot regions. CONCLUSIONS: In contrast to adult elite soccer players, adolescents demonstrate asymmetric foot loading patterns with increased peak loads in the lateral aspects of the nonpreferred foot. Our results may provide some explanation for MT V stress fractures that occur in elite adolescents.

Cementless femoral components in bicondylar hybrid knee arthroplasty in patients with rheumatoid arthritis: A 10-year survivorship analysis.

BACKGROUND: Total knee arthroplasty (TKA) has been established as a successful surgical treatment in the late stages of rheumatoid joint destruction. The purpose of this study was to review the clinical outcome and survivorship in rheumatoid arthritis (RA) patients undergoing TKA in hybrid technique with a cementless fixation of the femoral component. METHODS: We analysed retrospectively 66 RA patients who underwent 72 TKAs (P.F.C. Sigma®). Mean follow-up time was 124 ± 41 months. To evaluate postoperative clinical outcome, knee injury and osteoarthritis outcome score (KOOS) and Oxford knee score (OKS) were assessed. Kaplan-Meier analysis was used to calculate survivorship. The primary outcome was revision for any reason. RESULTS: Thirty-four patients (36 knees) died and two patients (2 knees) were lost to follow-up. Three patients (four knees) did not agree to participate. Twenty-seven patients (30 knees) were available for assessing clinical scores. The average scores were 85 ± 14 for KOOS and 34 ± 10 for OKS. In three patients (three knees), revision was necessary, including restricted range of motion ( n = 1), instability ( n = 1), and infection ( n = 1). There were no cases of loosening in this cohort study. The survival rates were 100% at 5 years, 97.1% at 10 years (95% CI 89.0-99.2%) and 95.6% at 15 years (95% CI 86.9-98.5%). CONCLUSIONS: This study confirms that excellent clinical results and a good 10-year survivorship can be obtained with hybrid fixation technique in TKA in the unique population of RA patients.

How do leg press exercises comply with limited weight bearing?

OBJECTIVES: To investigate foot loadings in different leg press settings with respect to a possible graduation of weight bearing (WB). DESIGN: Case series. SETTINGS: Assessing plantar force values by means of dynamic pedobarography taken place in orthopaedic departments' rehab center. PARTICIPANTS: 15 healthy students (9 men and 6 women, age 23 ± 2, weight 75 ± 6 kg) were recruited as participants from the medical faculty. MAIN OUTCOME MEASURES: Peak force values from normal gait (referred to as 100%) and single and double leg presses (SLP, DLP) with resistances of 10 kg, 20 kg and 40 kg, obtained with pedobarographic insoles. RESULTS: Performing DLP produced foot loadings (N) of 37 ± 15 with 10 kg, 91 ± 29 with 20 kg and 203 ± 27 with 40 kg, equal to 5%, 12% and 26% of full WB. SLP result in force values of 195 ± 32 with 10 kg, 308 ± 34 with 20 kg and 516 ± 45 with 40 kg, corresponding to 25%, 40% and 67% baseline. CONCLUSIONS: Leg press exercises can be performed in accordance with a given limitation of foot loading. Above mentioned conditions allow a graduation from 5% to 67% of full WB.

Incompliance of total hip arthroplasty (THA) patients to limited weight bearing.

INTRODUCTION: Limited weight bearing of the lower extremity is a commonly applied procedure in orthopedic rehabilitation following trauma surgery and joint replacement. The compliance of patients with limited weight bearing after cementless total hip arthroplasty has not yet been surveyed using sensor-loaded insoles. The objective of this study was to investigate foot loadings in patients after THA under the assumption of limited weight bearing. METHODS: Peak pressures for the hindfoot, midfoot and forefoot were obtained from 14 patients (10 women, 4 men, age 63 ± 12 years, height 172 ± 9 cm, weight 92 ± 20 kg, BMI 31 ± 6 kg/m(2)) by means of dynamic pedobarography, with full weight bearing preoperatively (baseline) and at 8-10 days after cementless total hip arthroplasty, walking again on even floor, and also walking upstairs and downstairs with a restriction of weight bearing to 10 % body weight, taught by an experienced physiotherapist with a bathroom scale. RESULTS: Foot loadings with limited weight bearing on even floor remained up to 88 % from full weight bearing preoperatively. Walking upstairs and downstairs under the same condition was approximately equal to a bisection of peak pressures from full weight bearing. CONCLUSIONS: Patients following cementless do not comply with limited weight bearing when they are trained by the use of a bathroom scale.

Introduction of a neutral shoe to assess reference values for dynamic pedobarography.

BACKGROUND: The aim of our study was to introduce a so-called "neutral shoe" as a tool to assess reference values for dynamic pedobarographic investigations. MATERIALS AND METHODS: Twelve healthy volunteers were asked to participate. During the first trial the participants were asked to walk with a neutral shoe (Breidbach, Germany). The second trial was performed with the running shoe "Faas 500" (Puma SE, Germany). Peak plantar pressure values were analyzed from nine foot regions using the Pedar® X system (Novel Inc., Munich, Germany). RESULTS: The mean peak pressure reduction for the total foot was 36% under the left (non-preferred) foot and 32% for the right (preferred) foot. A statistically significant reduction of peak pressure was observed for eight regions, from a mean 14% peak pressure reduction under the right metatarsal head 1 up to a 41% peak pressure reduction under the right big toe. CONCLUSIONS: The neutral shoe is a feasible tool to assess reference values for dynamic pedobarography. Such a reference tool may help to standardise several steps in the development and construction of shoes and orthotic devices.

Assessment of plantar pressure in hindfoot relief shoes of different designs.

BACKGROUND: Although there are several different concepts of hindfoot relief footwear, there are no studies on the extent of pressure reduction to be achieved by this footwear. Therefore, we sought to evaluate the reduction in plantar pressure to be achieved with two different hindfoot relief shoes. METHODS: Ten healthy volunteers performed three trials at a self-selected speed. Peak pressure values in mass-produced shoes (normal gait) were considered as 100% and were compared with measurements in two differently designed hindfoot relief shoes. Foot portions were defined as heel (0%-15% of total insole length), hindfoot (16%-30%), midfoot (31%-60%), and forefoot (61%-100%). RESULTS: Heel and hindfoot peak pressures were significantly reduced in both shoes compared with normal gait (P < .05), but the extent of peak pressure reduction under the heel and hindfoot varied significantly between the tested shoes. Midfoot peak pressure was not significantly reduced in tested shoes compared with baseline (P > .05) but differed significantly between the two shoes. Forefoot peak pressure was significantly reduced with one of the tested shoes (to a median 73% baseline; P = .004) but not with the other (median, 88% baseline). CONCLUSIONS: Hindfoot relief shoes leave a considerable amount of peak pressure, predominantly under the hindfoot. The extent of peak pressure reduction for the heel and the hindfoot varies between different hindfoot relief shoes. Depending on the affected foot area, the kind of hindfoot relief shoe should be carefully chosen.

Soccer boots elevate plantar pressures in elite male soccer professionals.

OBJECTIVE: The present study measured the difference in peak plantar pressure between running shoes and soccer shoes in male soccer professionals [mean (SD): age, 23 (4) years; height, 184 (7) cm; weight, 81 (6) kg]. DESIGN: Case series. SETTING: Institutional study. PARTICIPANTS: A total of 17 elite male soccer professionals [mean (SD): age, 23 (4) years; height, 184 (7) cm; weight 81 (6) kg]. INTERVENTIONS: Fifteen right and left steps with sensor-loaded insoles (99 sensors, 50 Hz) while running (3.3 m/s) in running shoes and then chosen soccer shoes (12-stud profile). The players were equipped with running shoes from the supplier without any medical supervision. MAIN OUTCOME MEASURES: Changes of peak plantar pressure for 9 defined foot portions between soccer boots and running shoes. RESULTS: A statistically significant increase of peak plantar pressure was found for the lateral midfoot (P < 0.001 for preferred and nonpreferred foot), the first metatarsal head (preferred foot: P < 0.001, nonpreferred foot: P = 0.002), the metatarsal heads 4/5 (preferred foot: P = 0.001, nonpreferred foot: P = 0.002), and the big toe (preferred foot: P = 0.001, nonpreferred foot: P < 0.001), but not for the lateral and medial hindfoot, the medial midfoot, and lesser toes. CONCLUSIONS: In running, soccer boots generate excessive foot loadings predominantly under the lateral midfoot, as compared with running shoes. Players should be trained with a thoughtfully designed workout regimen that allows performing as many straight running exercises as possible in running shoes instead of soccer boots. This may help to prevent fifth metatarsal stress fractures in elite male soccer players.

The Transient Chondrocyte Phenotype in Human Osteophytic Cartilage: A Role of Pigment Epithelium-Derived Factor?

OBJECTIVE: To identify factors that are responsible for the phenotypic differences between transient chondrocytes within human osteophytes prone to endochondral ossification and permanent chondrocytes within articular cartilage persisting for decades. METHODS: Differential gene expression of chondrocytes from human osteophytes or from articular cartilage was detected by cDNA microarray analysis. The expression of pigment epithelium-derived factor (PEDF), one of the most impressively differentially expressed genes, was validated by quantitative reverse transcriptase polymerase chain reaction as well as immunohistochemistry. The mode of action of PEDF was explored by cell viability assays and by detecting target genes. RESULTS: PEDF mRNA expression was upregulated by 118.5-fold (P = 0.01) in human osteophytic cartilage compared with articular cartilage, which was reflected by strong immunostaining for PEDF in the cartilaginous layer of osteophytes but largely negative staining in articular cartilage. Elevated levels of PEDF in osteophytes were associated with enhanced apoptosis. PEDF increased the expression of the proapoptotic factor FasL and induced cell death in cell culture. Osteochondral progenitor cells were more responsive to PEDF than differentiated articular chondrocytes. CONCLUSIONS: The induction of the proapoptotic factor PEDF within the osteophyte cartilage suggests a molecular concept for the transient chondrocyte phenotype that arises from progenitor cells and is prone to terminal differentiation and cell death.

Foot loading with an ankle-foot orthosis: the accuracy of an integrated physical strain trainer.

PURPOSE: To investigate the value of a built-in physical strain trainer for the monitoring of partial weight bearing with an ankle-foot orthosis. METHODS: 12 healthy volunteers were asked to perform three trials. Plantar peak pressure values from normal gait (trial one) were defined as 100% (baseline). The following trials were performed with the Vacoped® dynamic vacuum ankle orthosis worn in a neutral position with full weight bearing (trial two) and a restriction to 10% body weight (BW) (trial three), as monitored with an integrated physical strain trainer. Peak plantar pressure values were obtained using the pedar® X system. RESULTS: Peak pressure values were statistically significantly reduced wearing the Vacoped® shoe with full weight bearing for the hindfoot to 68% of the baseline (normal gait) and for the midfoot and forefoot to 83% and 60%, respectively. Limited weight bearing with 10% BW as controlled by physical strain trainer further reduced plantar peak pressure values for the hindfoot to 19%, for the midfoot to 43% of the baseline and the forefoot to 22% of the baseline. CONCLUSIONS: The Vacoped® vacuum ankle orthosis significantly reduces plantar peak pressure. The integrated physical strain trainer seems unsuitable to monitor a limitation to 10% BW adequately for the total foot. The concept of controlling partial weight bearing with the hindfoot-addressing device within the orthosis seems debatable but may be useful when the hindfoot in particular must be off-loaded.

Inaccuracy of a physical strain trainer for the monitoring of partial weight bearing.

OBJECTIVE: To investigate the use of a physical strain trainer for the monitoring of partial weight bearing. DESIGN: Case series with healthy volunteers. SETTING: Orthopedic clinic. PARTICIPANTS: Healthy volunteers (N=10) with no history of foot complaints. INTERVENTIONS: Volunteers were taught to limit weight bearing to 10% body weight (BW) and 50% BW, monitored by a physical strain trainer. MAIN OUTCOME MEASURES: The parameters peak pressure, maximum force, force-time integral, and pressure-time integral were assessed by dynamic pedobarography when volunteers walked with full BW (condition 1), 50% BW (condition 2), and 10% BW (condition 3). RESULTS: With 10% BW (condition 3), forces with normative gait (condition 1) were statistically significantly reduced under the hindfoot where the physical strain trainer is placed. All pedobarographic parameters were, however, exceeded when the total foot was measured. A limitation to 10% BW with the physical strain trainer (condition 3) was equal to a bisection of peak pressure and maximum force for the total foot with normative gait (condition 1). Halved BW (condition 2) left a remaining mean 82% of peak pressure and mean 59% of maximum force from full BW (condition 1). CONCLUSIONS: The concept of controlling partial weight bearing with the hindfoot-addressing device does not represent complete foot loading. Such devices may be preferably applied in cases when the hindfoot in particular must be off-loaded. Other training devices (eg, biofeedback soles) that monitor forces of the total foot have to be used to control partial weight bearing of the lower limb accurately.

Foot loading characteristics of different graduations of partial weight bearing.

Limited weight bearing of the lower extremity is a commonly applied procedure in orthopaedic rehabilitation after reconstructive forefoot surgery, trauma surgery and joint replacement. The most frequent limitations are given as percentage of body weight (BW) and represent 10 or 50% BW. The extent of foot loading under these graduations of partial weight bearing has not yet been described in detail. The objective of this study was to investigate forces at the foot-sole interface, which occur under graduated limitations of weight bearing. Peak pressure, maximum force, pressure-time integral and force-time integral (Pedar Cable) were assessed for a total of three trials with 10 healthy individuals. The results from limited weight bearing with 10 or 50% BW as taught by an experienced physiotherapist with a bathroom scale were referred to results of a normal gait. The limitation of weight bearing to 10% BW was equal to a bisection of peak pressure and maximum force for the total foot. Halved BW left a remaining 82% of peak pressure and 59% of maximum force for the total foot. We concluded that weight-bearing limitations to 10 and 50% BW lead to discernible differences in foot loading and may be applied to graduate forces of the lower limb for rehabilitation purposes. Foot loading with partial weight bearing exerts the percentage of BW and should be monitored to avoid an exertion of strains on the lower limb.

Chondromodulin 1 stabilizes the chondrocyte phenotype and inhibits endochondral ossification of porcine cartilage repair tissue.

OBJECTIVE: To investigate the effect of chondromodulin 1 on the phenotype of osteochondral progenitor cells in cartilage repair tissue. METHODS: Self-complementary adeno-associated virus (AAV) vectors carrying chondromodulin 1 complementary DNA (AAV-Chm-1) were applied to cartilage lesions in the knee joints of miniature pigs that were treated by the microfracture technique. Alternatively, isolated porcine osteochondral progenitor cells were infected with AAV-Chm-1 or with AAV-GFP control vectors ex vivo prior to being transplanted into cartilage lesions in which the subchondral bone plate was left intact. The quality of the repair tissue and the degree of endochondral ossification were assessed by histochemical and immunohistochemical methods. The effects of chondromodulin 1 overexpression were also analyzed by angiogenesis assays and quantitative reverse transcriptase-polymerase chain reaction. RESULTS: AAV-Chm-1-infected cells efficiently produced chondromodulin 1, which had strong antiangiogenic effects, as verified by the inhibition of tube formation of endothelial cells. Gene expression analyses in vitro revealed the cell cycle inhibitor p21WAF1/Cip1 as one target up-regulated by AAV-Chm-1. Direct application of AAV-Chm-1 vectors into microfractured porcine cartilage lesions stimulated chondrogenic differentiation of ingrowing progenitor cells, but significantly inhibited terminal chondrocyte hypertrophy, the invasion of vessel structures, and excessive endochondral ossification, which were otherwise observed in untreated lesions. Indirect gene transfer, with infection of porcine osteochondral progenitor cells by AAV-Chm-1 ex vivo, also supported chondrogenic differentiation of these transplanted cells. AAV-Chm-1-infected cells maintained a chondrocyte-like phenotype and formed a hyaline-like matrix that was superior to that formed by uninfected or AAV-GFP-infected cells. CONCLUSION: Our findings indicate that the antiangiogenic factor chondromodulin 1 stabilizes the chondrocyte phenotype by supporting chondrogenesis but inhibiting chondrocyte hypertrophy and endochondral ossification.

Combined arthroscopic and radiation synovectomy of the knee joint in rheumatoid arthritis: 14-year follow-up.

PURPOSE: To investigate the long-term outcome of combined arthroscopic and radiation synovectomy of the knee joint in early cases of rheumatoid arthritis (RA) with regard to knee function and the need for surgical re-interventions. METHODS: Between 1993 and 1997, a consecutive series of 38 RA patients with therapy-refractory synovitis of the knee joint and only mild cartilage lesions (not exceeding Outerbridge grade II at surgery) were treated with combined arthroscopic and radiation synovectomy. Knee function was assessed preoperatively; at 6 months, 1 year, and 5 years; and finally, at a mean of 14 years with 4 different functional scores. A Kaplan-Meier survival curve was calculated with "any re-intervention" and "total knee arthroplasty" as endpoints. RESULTS: Of 38 knees, 32 were available for the final 14-year follow-up with a total of 22 re-interventions: intra-articular steroid injection (n = 3), arthroscopic (n = 2) or radiation (n = 1) re-synovectomy, and total knee arthroplasty (n = 16). The remaining 10 patients with no re-intervention showed knee function not significantly different from the postoperative state. With any surgical re-intervention as the endpoint, the survival rate was 84% at 5 years (95% confidence interval [CI], 67.0% to 86.7%), 44% at 10 years (95% CI, 26.7% to 60.0%), and 32% at the 14-year assessment (95% CI, 16.0% to 49.3%). With total knee arthroplasty as the endpoint, the joint survival rate was 88.5% at 5 years (95% CI, 68.5% to 96.2%), 53.9% at 10 years (95% CI, 33.3% to 71.6%), and 39.6% at 14 years (95% CI, 18.9% to 48.6%). CONCLUSIONS: Combined arthroscopic and radiation synovectomy leads to a stable improvement of knee function for a minimum of 5 years, but surgical re-interventions were frequently observed at the 14-year assessment and challenge the long-term benefit of the procedure. Patients with no interventions had a significantly shorter history of disease (7 v 11 years). LEVEL OF EVIDENCE: Level IV, therapeutic case series.

17-year follow-up of the rough-blasted threaded Weill cup in uncemented total hip arthroplasty.

INTRODUCTION: For uncemented hip arthroplasty, various cup designs are available. The threaded Weill acetabular component (Weill cup; Zimmer, Winterthur, Switzerland) has been used for more than 20 years, with poor results of the smooth threaded design. Our study was intended to assess the 17-year outcome of the rough-blasted option of the threaded Weill cup. MATERIALS AND METHODS: Between 1987 and 1988, a series of 86 rough-blasted threaded Weill cups were implanted in combination with the CLS Spotorno stem (Zimmer Ltd, Germany) The patients' mean age at the time of surgery was 50 years (range 19-67 years). 67 out of 86 hips (78%) were available for a follow-up at a mean of 17 years (range 16-18 years). Radiographs were available from 55 out of 63 unrevised hips (87%) and analyzed for radiolucency and PE wear. RESULTS: Two out of 86 cups (3%) were revised due to aseptic loosening and another two cups (3%) were awaiting revision for the same reason. Ten patients (10 cups, 12%) were lost to follow-up, and nine patients with nine cups (11%) had deceased without radiographic signs of cup failure. Cup survival with "revision or awaiting revision" as endpoint was 86% (95% CI 75-92%). No deep infections occurred, and no polyethylene insert was exchanged. The Harris hip score was excellent in 37 out of 67 clinically examined hips (55%), good in 18 hips (26%), satisfactory in 5 hips (8%) and moderate or poor in 5 hips (8%) and 2 hips (3%), respectively. CONCLUSION: The rough-blasted threaded Weill cup provides a good long-term performance in cementless total hip arthroplasty. The results compare favourably to the smooth threaded cup design.

Seventeen-year survival of the cementless CLS Spotorno stem.

INTRODUCTION: For primary uncemented hip arthroplasty, various stem designs are available. The cementless CLS((R)) Spotorno stem has been used for more than 20 years. We re-evaluated a group of patients previously examined for a 10-year follow-up to assess the clinical and radiological stem performance in the long run. MATERIALS AND METHODS: Between 1987 and 1988, a consecutive series of 107 uncemented CLS((R))-Spotorno stems (Zimmer Ltd., Germany) were implanted in 94 patients. The patients' mean age at the time of surgery was 51 years (range 20-77 years); 80 hips out of 107 (86%) were available for a clinical examination [Harris Hip Score (HHS)] after a mean of 17 years (range 15-18 years). In addition, radiographs were available from 74 out of 80 examined hips (92%) and analyzed for radiolucency, stress shielding, stem migration and heterotopic ossification. RESULTS: Stable stem fixation was present in 64 hips (98.5%). With "non-traumatic loosening" as an endpoint, stem survival was 100% after 17 years. Two stems (3%) showed mild subsidence already in the 10-year follow-up with no progression after 17 years. The HHS described excellent results in 47 hips (59%), good results in 16 hips (20%) and fair or poor results in 7 hips (9%) and 10 hips (13%), respectively. Radiolucency and grades II and III stress shielding were progressive at 17 years compared with the 10-year results. Grade IV stress shielding associated with osteolysis was seen in 9 hips (14%). Thigh pain was present in 20 hips (25%). CONCLUSION: The CLS((R)) Spotorno stem allows excellent long-term results in cementless hip arthroplasty, leaving only minimal options for substantial improvements. Our findings on progressive stress shielding point towards a more diaphyseal load transfer of the CLS stem.

Synovectomy of the hip in patients with juvenile rheumatoid arthritis.

BACKGROUND: There is a lack of data on the functional effect of open hip synovectomy in a large number of patients with juvenile rheumatoid arthritis evaluated with a validated assessment tool. METHODS: Between 1985 and 1997, sixty-seven open hip-joint synovectomies were carried out in fifty-six patients with juvenile rheumatoid arthritis. Fifty-five hips (82%) had radiographic changes that were stage III or higher according to the system of Larsen et al. Hip function was evaluated preoperatively and after a mean of fifty months with the Merle d'Aubigné hip score. RESULTS: Sixty-five (97%) of the sixty-seven hips were available for follow-up. The mean total Merle d'Aubigné hip score (and standard error of the mean) was significantly improved from 9.5 +/- 2.5 points at baseline to 16.3 +/- 1.0 points at the time of follow-up (p < 0.001). The individual scores for pain, mobility, and walking ability were significantly increased as well (all p < 0.001). Eighty-five percent of the hips were observed to have a very great or great improvement in function. A concomitant soft-tissue release was performed in seven hips, and nine hips required surgical dislocation. Surgical complications included two superficial wound hematomas that did not require intervention; osteonecrosis of the femoral head was not observed. Five hips required total hip arthroplasty during the follow-up period. Thus, the survival rate for the hips was 94% at a mean of four years following the synovectomy. CONCLUSIONS: Open hip synovectomy in patients with juvenile rheumatoid arthritis is a safe procedure that can improve hip-joint function for up to five years.

Extensor indicis-transfer compared with palmaris longus transplantation in reconstruction of extensor pollicis longus tendon: a retrospective study.

Either an extensor indicis transposition (EIT) or an intercalated free tendon graft (FTG) can be used for secondary reconstruction of the extensor pollicis longus (EPL) tendon. We reviewed 1469 cases of extensor tendons repaired between 1992 and 2003 and compared the results. In only 55 patients was an isolated secondary reconstruction of the EPL done. Forty-five patients (82%) were available for clinical follow-up after a mean of 4.3 (range 2-11) years (28 (62%) who had EIT and 17 (38%) who had FTG). Thumb function was assessed postoperatively using Geldmacher's criteria, and the uninjured thumb served as control. The comparison showed no significant differences between the procedures for the single variables evaluated, or for the injured and other (uninjured) thumb in either group. For isolated secondary reconstruction of the EPL tendon, both the extensor indicis transposition and a free autologous tendon graft successfully restore thumb function. Therefore, both surgical techniques can be considered equal alternatives.

Assessment of plantar pressure in forefoot relief shoes of different designs.

BACKGROUND: After reconstructive forefoot surgery, patients require complete or partial forefoot relief, which can be obtained with a variety of shoe designs. The aim of this study was to evaluate the effectiveness of two different types of forefoot-relief shoes frequently used after surgery, especially their safety against unintentional forefoot load. METHODS: Ten healthy volunteers were asked to perform five trials on a treadmill at self-selected speeds. In the first trial, mean peak pressure values in mass-produced shoes and insoles were evaluated and considered as 100%. Two different shoe designs (short heel-short sole, ii: short heel-complete sole) were compared in two trials each with appropriate and inappropriate use (attempting to put weight on the forefoot) gait pattern. Plantar pressure values were obtained using the Pedar cable system (Novel Inc., Munich, Germany). For analysis, pedobarographic pictures were subdivided into midfoot (31% to 60% of the total insole length) and forefoot (61% to 100% of the total insole length). ANOVA was used for statistical analysis, and p values less than 0.01 were considered significant. RESULTS: With the short-soled shoe, forefoot and midfoot relief was 100% in both compliant and in noncompliant use. With wearing a complete sole, compliant use led to a significant reduction (p < 0.01) of mean peak pressure under the forefoot (34 +/- 13% remaining) and midfoot (47 +/- 13% remaining). Noncompliant use of the complete-sole shoe produced mean peak pressure values significantly higher (p < 0.01) than normal gait in mass produced shoes under the forefoot, but not under the midfoot. CONCLUSIONS: Forefoot-relief shoes are effective in reducing both mean and peak plantar pressures. Shoes with a nonsupported midfoot and forefoot may be safer with inappropriate use than shoes with a complete sole. The kind of forefoot shoe should be carefully chosen to regulate weightbearing after reconstructive forefoot surgery.

Site-specific intraoperative efficacy of arthroscopic knee joint synovectomy in rheumatoid arthritis.

PURPOSE: To assess the intraoperative reduction of inflammatory infiltrates achieved by arthroscopic knee joint synovectomy in patients with rheumatoid arthritis (RA) with special regard to the removal site, using preoperative and postoperative synovial tissue (ST) samples. TYPE OF STUDY: A histologic and immunohistochemical study. METHODS: Eleven patients with treatment-refractory RA knee synovitis underwent arthroscopic synovectomy. In each patient, ST specimens were obtained immediately before and after synovectomy from 9 defined sites covering the whole joint. The samples were graded using an acute synovitis score (ASS; presence of polymorphonuclear neutrophilic leukocytes [PMN] and fibrin) and a chronic synovitis score (CSS; e.g., lining cell hyperplasia, presence of diffuse and lymphoid aggregates). Immunohistologic analyses were performed using 7 monoclonal antibodies directed against PMN, macrophages, and T-cell subsets (total of 1,584 preparations). Knee function was assessed after an average follow-up of 28 months by Lysholm score (modified by Klein and Jensen), Insall functional and knee scores, and Lequesne score. RESULTS: Arthroscopic synovectomy led to an overall significant (P between .005 and .05) reduction of the acute inflammatory infiltrates (ASS) by 82.1%, but to a significant reduction of chronic inflammatory infiltrates (CSS) by only 62.5%. Accordingly, the density of PMN was reduced by 81.8%, whereas that of macrophages and different T-cell subsets was only decreased by < or = 61.6%. With respect to the anatomic regions, a significantly (P < or = .05) less marked reduction of inflammatory infiltrates was observed in the upper lateral and central recess, at the medial and lateral capsule, as well as at the femoral insertion of the anterior cruciate ligament. All knee joint scores showed a significant (P < or = .01) improvement over preoperative values at follow-up. CONCLUSIONS: Arthroscopic synovectomy effectively reduces acute and chronic inflammatory infiltrates in patients with RA who have refractory synovitis of the knee joint (immediately after synovectomy) and improves knee function (28-month follow-up). However, the reduction of inflammatory infiltrates appears to depend on the anatomic region of the joint. LEVEL OF EVIDENCE: Level III.