Diagnostic utility of open biopsy in patients with two culture-negative aspirations in the diagnostic work-up of periprosthetic joint infection.

INTRODUCTION: Different approaches have been proposed for bacterial identification in patients with a suspected periprosthetic joint infection (PJI). If a one-stage procedure is considered, a higher rate of preoperative bacterial identification can be achieved if biopsy is included in the diagnostic work-up. The performance of open biopsy (OB) in the context of PJI has not been clearly determined yet. The purpose of this study was to determine the value of an OB added to two consecutive culture-negative joint aspirations during PJI workup. MATERIALS AND METHODS: We retrospectively analyzed the OB data from a single institution. Patients under PJI work-up of the hip or knee with two culture-negative periprosthetic aspirations who underwent OB were included. Sensitivity and specificity were calculated using the musculoskeletal infection society (MSIS) criteria as gold standard. Patients undergoing urgent irrigation and debridement and patients with history of surgery to the affected joint in the prior 6 weeks were excluded. RESULTS: 126 patients were included in this study. 62 (49.2%) patients had prior revisions, 48 of them due to PJI. The sensitivity and specificity of OB was 69.4% and 89.1%, respectively. The OB procedure led to the identification of the causative germ in 50 out of 126 (40%) cases so they could undergo one-stage (septic) exchange. CONCLUSION: The OB is a valuable resource if preoperative synovial fluid cultures are negative, a high suspicion of infection persists and a one-stage procedure is preferred. It intends bacteria identification and allows surgeons to evaluate prosthetic complications for further surgical procedures.

What Is the Dislocation and Revision Rate of Dual-mobility Cups Used in Complex Revision THAs?

BACKGROUND: Dual-mobility cups have been shown to reduce the dislocation risk after THA. Although dual-mobility cups can be a useful strategy to mitigate against recurrent dislocation after revision surgery, few clinical studies have focused on the results of complex revision THAs with extensive bone and soft-tissue loss or in patients who have undergone more than one previous surgical procedure. QUESTIONS/PURPOSES: (1) What is the survival free from revision for dislocation of dual-mobility cups used in complex revision THAs? (2) What is the survival free from any dislocation? METHODS: Between January 1, 2009 and December 31, 2013, 327 patients underwent a complex revision THA that included an acetabular revision, defined as preexisting massive bone loss in the acetabulum (at least Paprosky Type 2B) and/or proximal femur (at least Paprosky Type 3), substantial gluteal soft-tissue involvement, at least two previous surgical procedures or a one-stage septic revision, or history of dislocation. All 327 complex revision patients received a dual-mobility cup. Of those, 34% (111) were lost to follow-up before 5 years and were not known to have reached a study endpoint (revision for dislocation, and any dislocation) before then, leaving 216 patients for analysis. For patients with bilateral hip surgeries only the first operated hip was included for analysis. The median (range) follow-up duration was 69 months (60 to 110). The primary endpoint was dislocation or re-revision for dislocation. Fifty-six percent (120 of 216) of the patients were women and 44% (96 of 216) were men. The mean age of the patients was 69 ± 9 years. The patients underwent a median of four surgical procedures (1 to 4) before the index procedure (the revision evaluated in this study). A survival analysis was performed using the Kaplan-Meier method; any dislocation or revision for dislocation was determined as the endpoint. RESULTS: The dislocation-free survival rates were 96% (95% confidence interval 92 to 98) at 5 years and 82% (95% CI 72 to 89) at 9 years. The overall dislocation rate was 11% (24 of 216 patients) at the final follow-up interval. Survival free of revision for dislocation was 99% (95% CI 96 to 100) at 5 years and 85% (95% CI 75 to 92) at 9 years. CONCLUSIONS: Dual-mobility cups used in complex revision THA in this series had a higher rate of dislocation and revision than expected, based on earlier studies of dislocations of these components. Although we believe dual-mobility cups are still the first choice of implant if the patient has instability, these cups should be used cautiously if severe bone loss or soft-tissue involvement is present. LEVEL OF EVIDENCE: Level III, therapeutic study.

Midterm Results After Tantalum Cones in 1-Stage Knee Exchange for Periprosthetic Joint Infection: A Single-Center Study.

BACKGROUND: The use of tantalum cones to reconstruct extensive bone defects in revision total knee arthroplasty has been established. We aimed to evaluate the midterm results after 1-stage knee exchange for periprosthetic joint infection using tantalum cones. METHODS: Seventy-two patients (mean age, 70 ± 8.2 years) treated with a 1-stage exchange for infected total knee arthroplasty using porous tantalum cones, between 2011 and 2016, were retrospectively included. Either rotating or pure hinge system in combination with femoral and/or tibial cones was used. Survivorship analysis (septic and aseptic) was performed. Prospectively, functional outcome was assessed at a mean follow-up of 49.9 ± 18.8 months (range, 24-88). RESULTS: A total of 15 patients (21%) were rerevised, 8 (11.1%) for infection and 7 (10%) for aseptic loosening, requiring cone exchange in 12 patients (17%). Cone-related survival free from any revision was 83% ± 3.8 standard deviation (95% confidence interval, 74-90), and infection-free survival was 89% ± 4.2 standard deviation (95% confidence interval, 76-93). No significant correlation was reported between the types of prosthesis used (P = .8) or implanted cones and failure (P = .6). History of a previous septic revision increased the risk of cone revision after the index surgery (P < .001). Preoperative Hospital for Special Surgery knee score improved from 47 ± 16 (range, 14-87) to 60 ± 17 (range, 24-84) points at the latest follow-up. CONCLUSION: First study reports on outcomes of the 1-stage exchange using tantalum cones for knee periprosthetic joint infection with additional severe bone loss. Midterm cone-related and infection-free survival offered good results and provided reasonable functional outcomes.

Interprosthetic Femoral Sleeves in Revision Arthroplasty: A 20-Year Experience.

BACKGROUND: Interprosthetic femoral fractures in patients with ipsilateral stemmed total hip arthroplasty (THA) and total knee arthroplasty (TKA) can be technically demanding to treat surgically. Nonunion and implant failure are among the main complications following fixation of interprosthetic femoral (IF) fractures. Total femoral arthroplasty (TFA) is associated with a high incidence of infection and instability. IF sleeves have been designed to avoid the disadvantages of these techniques and to provide a stable construct. The aim of this study was to present the results with this device from a single center. METHODS: We reviewed 26 patients who underwent revision arthroplasty procedures, using custom-made cemented IF sleeves between 1997 and December 2017 in our institution. Two-part sleeves were used in 18 patients and one-part sleeves in 8 patients. The most common indication was an IF fracture (18 patients). Patients were monitored for postoperative complications, implant failure, and re-revision. The minimum follow-up of the survivors with nonrevised sleeves was 12 months. RESULTS: Twenty-three patients were included for the final analysis. The mean survivorship of the IF sleeve was 4.6 years at latest follow-up (mean 48.5 months; range 12 to 156). The overall rate of complications was 47.8%. The rate of mechanical failure was 21.7%. Late infections occurred in 3 patients (13%). At the latest follow-up, the mean Harris Hip Score was 69.9 points (range 39 to 94), and the mean functional Knee Society Score was 42.5 points (range 0 to 90), with average knee flexion of 95° (range 90° to 100°). CONCLUSION: The IF sleeve is a valid technique for the management of selected patients with IF fractures, particularly when a stable fracture fixation is not possible. Hip instability is not a concern, and functional improvement is achievable. Careful planning is required preoperatively to avoid mechanical failure.

Kellgren-Lawrence scoring system underestimates cartilage damage when indicating TKA: preoperative radiograph versus intraoperative photograph.

INTRODUCTION: The Kellgren-Lawrence score helps the orthopedic surgeon to classify the severity of knee osteoarthritis (OA) before total knee arthroplasty (TKA). There might be a discrepancy between subjective complaints of the patients and radiologically visible changes of the knee joint in many cases. In this context, we performed a prospective clinical study to compare the preoperative degree of knee OA using the Kellgren-Lawrence score with the intraoperative extent of cartilage damage during primary TKA. MATERIALS AND METHODS: A total of 251 primary TKA surgeries due to a primary knee OA were prospectively included. Preoperative Kellgren-Lawrence score was determined using standardized preoperative plain radiographs of three views; anteroposterior, lateral and skyline of the patella by a senior radiologist. Intraoperatively, in all cases, photographs of the medial, lateral, and patellofemoral joint compartments were taken. Using the International Cartilage Repair Society (ICRS) score, the degree of chondromalacia was assessed. Subsequently, correlation analysis was performed using the Pearson-Clopper 95% confidence interval (CI). RESULTS: There were higher intraoperative scores compared to the preoperative scores in 160 of all cases (63.7% of 251, 95% CI 57.5-69.7%). A mismatch of two score grade points was found in 8.4% (95% CI 5.3-12.5%). The most common mismatch was noted in patients with preoperative Kellgren-Lawrence score of 3 and an intraoperative score of 4 in 48.2% (95% CI 41.9-54.6%). CONCLUSIONS: The preoperative radiographs using Kellgren-Lawrence underestimate the severity of knee osteoarthritis. The true extent of articular cartilage damage can be better appreciated intraoperatively. In patients undergoing primary TKA, the correlation of clinical symptoms with radiological findings is crucial in deciding when to perform the surgery. Besides, other imaging modalities may be used as an adjunct when the clinical findings and plain radiographs do not correlate.

[Arthroplasty in patients with osteoporosis]. / Endoprothetik bei Patienten mit Osteoporose.

Arthroplasty has become a very successful operation with excellent long-term results. A dedicated diagnostic set-up to exclude osteoporosis prior to a joint replacement and the use of drugs to improve the outcome of a joint replacement are currently not recommended. Knee arthroplasty should always be cemented in patients with known osteoporosis. The same is recommended for hip joint replacement, even if the cement-free acetabular component yields good results. Rapid loading and mobilization appear beneficial also with respect to the osteoporosis and its systemic treatment.

Severe metallosis and elevated chromium in serum following implantation of the joint unloading implant system.

In recent years, the minimally invasive joint-preserving implant system has been developed. The main goal of this device is to unload the medial knee compartment without affecting the lateral compartment. The current authors describe a severe metallosis and elevated chromium in serum following implantation of the joint unloading implant system of a 50-year-old male patient, presented to our hospital 3 years after implantation of a KineSpring System into his left knee due to unicompartmental medial osteoarthritis (OA) in an external hospital. Radiographs showed radiological signs for loosening of the screws in the tibia and a progressive OA on the medial and patellofemoral compartments. Revision surgery with removing of the unloading device was performed at our hospital. The intraoperative situs presented a severe metallosis around the device. Five days after revision surgery, the laboratory parameters revealed an elevated value for chromium in serum, while nickel and cobalt values in serum were normal. Reliable clinical data about the long-term results of the KineSpring System is desperately needed. Further studies are warranted to work out the effects of cobalt and chromium levels and further side effects following the implantation of the extra-articular absorber system.

Allergic reactions in arthroplasty: myth or serious problem?

PURPOSE: The purpose of this study was to determine the prevalence of sensitisation to chromium, cobalt, nickel, or a cement component in patients who received endoprosthetic surgery at our institution. Also, we aimed to assess the portion related to allergic reactions in endoprosthetic revisions and to follow-up those patients after allergic reaction related revisions. METHODS: We selected patients with a pre-operative known sensitisation to chromium, cobalt, nickel, or a cement component for a post-operative allergic reaction. All patients who received revision surgery because of a potential allergic reaction were followed up post revision surgery. RESULTS: Eight hundred fifty-five patients were pre-operative known to have a sensitisation to chromium, cobalt, nickel, or a cement component. Six hundred eighty-two patients (79.8 %) received a primary arthroplasty, and 173 patients (20.2 %) received a revision surgery. Seventeen patients (2.0 %) were revised because of allergic reactions. Allergic reactions were the cause for approximately 0.2 % of all endoprosthetic revisions and for 9.8 % of revisions in patients with sensitisation to one of the reviewed components. Potential allergens were strictly avoided in the replaced prosthesis. Outcome scores improved post-operatively. CONCLUSIONS: The allergic patient should be thoroughly informed about potential reactions resulting from implant choice. Our study can serve as risk assessments by quantifying the incidence of allergic reactions due to endoprosthetic treatment.

Influence of tibial rotation on tibial tunnel position measurements using lateral fluoroscopy in anterior cruciate ligament reconstruction.

PURPOSE: The purpose of the current study was to evaluate the influence of internal and external knee rotation on tibial tunnel position measurements in anterior cruciate ligament reconstruction using the Amis and Jakob line. METHODS: Anatomic double bundle ACL reconstruction was performed in seven cadaveric knees. Afterwards, the knees were CT scanned, and 3D CT models were established. Utilizing these models, strict lateral and radiographs with the knees in 5°, 10°, and 20° of internal as well as external rotation were established. Using these radiographs, the positions of the anteromedial (AM) and posterolateral (PL) tibial tunnels were measured using the Amis and Jacob line. The tunnel positions of the strict lateral were compared to the rotated radiographs. To assess the inter- and intraobserver reliability, two independent observers measured the tunnel positions, and one observer measured twice. RESULTS: Significant differences for the AM tunnel position were observed if more than 10° of external or 20° of internal rotation were applied. For the PL tunnel position, no significant differences were found between the strict lateral and the rotated radiographs. Inter- and intraobserver reliability was good. CONCLUSIONS: The accuracy of the Amis and Jakob line is dependent on the degree of knee rotation and the position of the measured tunnel. Therefore, when using the Amis and Jakob line to determine the tibial tunnel position during surgery, attention should be paid to rotational alignment of lateral radiographs. However, the maximum rotation tested in the present study (20°) showed only a difference in tunnel position of 3.3 % compared to optimal rotational alignment. Thus, in most cases, the effects of minor malrotation on tunnel position measurement should be of minimal clinical significance.

Total Hip Arthroplasty in Patients with Skeletal Dysplasia.

127 patients with a height ≤ 150 cm (non metric ≤ 4 feet and 11 inches) who received hip arthroplasty surgery between July 1, 2006 and May 30, 2013 at our institution were enrolled. Retrospective data evaluation was performed for two different times of follow-up (1 year and 5 years respectively). 115 patients were evaluated for 1-year follow up. Out of these, 27 patients were available for 5-year follow up. The mean Harris Hip Score increased from 40 ± 13 on admission to 82 ± 20 (P<0.001) at 1-year follow-up and 79 ± 17 (P<0.001) at 5-year follow-up. Hip arthroplasty can be performed in patients with dwarfism with good clinical benefits. However, survival rates are worse compared to the general population.

Treatment of Vancouver type B2 periprosthetic femoral fractures.

PURPOSE: Stem loosening in both cemented and uncemented total hip arthroplasty is the hallmark of the Vancouver type B2 classification of periprosthetic hip fractures. METHODS: We discuss the technique we use at our institution for treating these fractures. RESULTS: Periprosthetic femoral-shaft fractures are associated with a relatively high mortality rate, approximating that of patients with hip fractures. Outcomes are directly associated with early mobilisation and construct stability. CONCLUSIONS: We recommend performing the procedure only when the surgeon is proficient in revision hip surgery and trauma care. A well-selected portfolio of different stem designs and an array of osteosynthesis devices should be available, as well.

Total knee arthroplasty in patients with skeletal dysplasia.

INTRODUCTION: Dwarfism is a challenge in arthroplasty. The anatomical features provide a lot of pitfalls. The aim of this study was to follow-up growth-restricted patients after endoprosthetic treatment. MATERIALS AND METHODS: 138 knee arthroplasties in patients with a height ≤150 cm between January 1, 2000 and May 5, 2013 at our institution were enrolled in this study. 124 cases were available for 1-year follow-up. Out of these, 43 cases were available for 5-year follow-up so far. 14 patients were lost to follow-up. RESULTS: IKS score increased from 35 ± 16 on admission to 67 ± 22 (p < 0.001) at 1-year follow-up and 65 ± 23 (p < 0.001) at 5-year follow-up. Function Score increased from 40 ± 29 on admission to 64 ± 21 (p < 0.001) at 1-year follow-up and 63 ± 23 (p < 0.001) at 5-year follow-up. Revision surgery was required in one case (0.8 %) after 1-year follow-up, and in an additional three cases (7 %) after 5-year follow-up. CONCLUSIONS: Knee arthroplasty can be performed in patients suffering from dwarfism with good clinical benefits. However, survival rates are worse compared to the general population.

Excluding infections in arthroplasty using leucocyte esterase test.

PURPOSE: Periprosthetic joint infections remain a major challenge for the surgeon in modern arthroplasty. The decision on how to handle a case is often difficult due to the variety of clinical presentations. The aim of this study was to establish the leucocyte esterase test as an intra-operative rapid diagnostic tool in an unclear infected or aseptic situation. METHODS: In the setting of 364 endoprosthetic joint procedures on knee, hip and shoulder, we aspirated synovial fluid before performing capsulotomy. We performed a leucocyte esterase test. The results were correlated with the pre-operative synovial fluid aspirations, the laboratory blood sample parameters (C-reactive protein, white blood cells) and the intra-operative histopathological and microbiological findings. RESULTS: The leucocyte esterase test has a sensitivity of 100% and a specificity of 96.5%. The positive predictive value was 82% and the negative predictive value was 100%. Correlation with conventional methods such as serum C-reactive protein and serum white blood cells is given. The histopathological evaluation confirmed the microbiological results in all but three cases. CONCLUSIONS: Based on our results and the current literature, we recommend the leucocyte esterase test as a useful tool in the diagnosis of periprosthetic joint infection.

Effectiveness of an autologous transfusion system following cemented and non-cemented revisions of total hip arthroplasty.

PURPOSE: The goal of this study was to analyse the efficacy of blood autotransfusion using a continuous autologous transfusion system in revisions of total hip arthroplasty (THA). We looked at whether administration of allogeneic blood units was reduced in these cases and if there is a difference between cemented and non-cemented revisions. METHODS: Between January 2011 and December 2011, patients being treated with revision THA were included (n = 411). The following parameters were analysed: patient age, gender, weight (kg), height (cm), body mass index (BMI, kg/m(2)), surgical diagnosis, treatment and American Society of Anesthesiologists (ASA) classification score. The difference between pre- and post-operative haemoglobin (Hb, g/dl), amount of peri-operative blood loss (ml), amount of retransfused washed shed blood and amount of allogeneic and/or autologous transfusion (ml) were recorded. RESULTS: In both the cemented and non-cemented revision THA groups, there was no significant difference between pre- and post-operative Hb with or without using an autotransfusion system. In 92 of 186 cemented cases using an autologous transfusion system (49.5%) and 38 of 117 non-cemented cases using an autologous transfusion system (32.5%), allogeneic blood transfusion (ABT) was required. Cemented procedures using an autologous transfusion system got significantly more ABTs than non-cemented procedures using an autologous transfusion system (p = 0.0042, odds ratio = 2.035). CONCLUSIONS: Use of an autologous transfusion system did not reduce the amount of ABT in revision THA in the patient cohort reported here. In our opinion, general blood management is required before and during surgery to reduce administration of ABT.

Common causes of failed unicompartmental knee arthroplasty: a single-centre analysis of four hundred and seventy one cases.

PURPOSE: We performed this retrospective study to determine the main causes for early and late failures of unicompartmental knee arthroplasty (UKA). METHODS: Between January 2000 and March 2012, all patients treated for a failed medial UKA in the authors' institution were retrospectively reviewed. A total of 471 patients were identified, and causes of failure were analysed based on the medical records and radiographs at the time of revision. RESULTS: The cohort included 161 males and 310 females, with a mean age of 67.7 years (range, 42-91 years; SD = 10.1) at the time of revision. The mean time from index arthroplasty to revision surgery was 6.1 years (range, 0.1-27.9 years; SD = 5.6). A total of 254 cases (53.9 %) failed within five years after primary implantation, and 108 cases (22.9 %) failed after ten years. The major reason for failure was the development of other compartment arthritis (39.5 %), followed by aseptic loosening (25.4 %). CONCLUSIONS: Of importance, the mean time to failure after UKA was 6.1 years, with more than 50 % of failures occurring within the first five years postoperatively.

CaReS (MACT) versus microfracture in treating symptomatic patellofemoral cartilage defects: a retrospective matched-pair analysis.

BACKGROUND: Treating patellofemoral articular cartilage lesions remains a challenging task in orthopedic surgery. Whereas microfracture and autologous chondrocyte implantation yield good results on femoral condyles, the therapeutic state of the art for treating patellofemoral lesions is yet to be determined. In this study, we compared the CaReS technique, which is a matrix-associated autologous chondrocyte implantation technique, to microfracture for treating patellofemoral articular cartilage lesions. METHODS: Between May 2003 and December 2005, 17 patients with an isolated patellofemoral cartilage defect (International Cartilage Repair Society III/IV) were treated with the CaReS technique at our department. After adjusting for inclusion and exclusion criteria, ten of these patients could be included in this study; ten patients treated with microfracture were chosen as a matched-pair group. Clinical outcome was evaluated 3 years after surgery by the 36-item Short Form Health Survey Questionnaire (SF-36), International Knee Documentation Committee (IKDC) subjective evaluation of the knee, Lysholm Score, and Cincinnati Modified Rating Scale scores. RESULTS: Patients treated with CaReS had statistically significantly improved IKDC, Lysholm, and Cincinnati scores 36 months after surgery compared with preoperatively. When comparing outcome between groups 36 months after surgery, there was no statistically difference in IKDC, Lysholm, and Cincinnati scores. CONCLUSIONS: This is the first trial comparing the CaReS technique and microfracture for treating patellofemoral articular cartilage lesions, and results show that CaReS(®) yields comparable results to microfracture. The small number of patients is a limiting factor of the study, leading to results without statistical significance. A multicentric prospective randomized study comparing the two procedures is desirable.

Enhanced migration of human bone marrow stromal cells in modified collagen hydrogels.

PURPOSE: Collagen I hydrogels are widely used as scaffolds for regeneration of articular cartilage defects. We hypothesised that ingrowth might be improved by removing the superficial layer of a compressed hydrogel. The control group consisted of the original unmodified product. METHODS: The migration of human bone marrow stromal cells (hBMSCs) into the hydrogel was evaluated by confocal microscopy. We quantified the DNA concentration of the hydrogel for each group and time point and evaluated the chondrogenic differentiation of cells. RESULTS: After one week, the detectable amount of cells at the depth of 26-50 µm was significantly higher in the modified matrix (MM) than in the non-modified matrix (NM) (p = 0.011). The maximum depth of penetration was 75 µm (NM) and 200 µm (MM). After three weeks, the maximum depth of penetration was 175 µm (NM) and 200 µm (MM). Likewise, at a depth of 0-25 µm the amount of detectable cells was significantly higher in the MM group (p = 0.003). After 14 days, the concentration of DNA was significantly higher in the samples of the MM than in the control group (p = 0.000). Staining of histological sections and labelling with collagen II antibodies showed that a chondrogenic differentiation of cells in the scaffold can occur during in vitro cultivation. CONCLUSIONS: Removing the superficial layer is essential to ensuring proper ingrowth of cells within the compressed hydrogel. Compressed hydrogels contribute better to cartilage regeneration after surface modification.

Treatment of osteochondral fractures of the knee: a meta-analysis of available scientific evidence.

PURPOSE: Although traumatic osteochondral fractures of the knee represent a common pathology of the knee joint, there is no general agreement concerning specific treatment of this entity. This meta-analysis was initiated in order to evaluate scientific evidence on different treatment options for acute osteochondral fractures of the knee. METHODS: For this purpose an OVID-based systematic literature search was performed including the following databases: MEDLINE, MEDLINE preprints, Embase, CINAHL, Life Science Citations, British National Library of Health and Cochrane Central Register of Controlled Trials. The literature search period was from 1946 to January 2012, which led to the identification of 1,226 articles. After applying study-specific inclusion criteria a total of 19 studies with clinical follow-up of 638 patients were included. The methodology of these studies was systematically analysed by means of the Coleman Methodology Score. Outcome and success rates were evaluated depending on treatment applied. RESULTS: All studies (n = 19) identified represent case series (evidence-based medicine level IV) and included a total of 638 patients. The average post-operative follow-up was 46 ± 27 months (range 3.75-108). The mean number of study subjects per study was 33 ± 44 patients (range 4-169). The average Coleman Methodology Score was 29 ± 17 points (range 5-72). Six different scoring systems were used for clinical assessment. The overall clinical success rate was 83% and varied between 45 and 100%. CONCLUSIONS: This meta-analysis reveals a significant lack of scientific evidence for treatment of osteochondral fractures of the knee. No valid conclusion can be drawn from this study concerning the recommendation of a specific treatment algorithm. Nevertheless, the overall failure rate of 17% underlines that an acute osteochondral fracture of the knee represents an important pathology which is not a self-limiting injury and needs further investigation.

Failed joint unloading implant system in the treatment of medial knee osteoarthritis.

In the setting of end-stage osteoarthritis of the knee, total knee arthroplasty is the gold-standard treatment. Recently, a minimally invasive, joint preserving treatment option in the treatment of medial osteoarthritis of the knee has been developed. It is called the KineSpring(®) (Moximed(®) International GmbH, Zurich, Switzerland). The goal of this novel device is to reduce medial compartment loading without significantly affecting the loading of the lateral compartment. In this context, the current authors present a case of device failure using these new implants, which at 7 months post-op necessitated revision surgery with complete removal of the device.

Practice in rehabilitation after cartilage therapy: an expert survey.

BACKGROUND: Current cartilage therapy modalities like microfracture, ACT/MACT, AMIC or osteochondral transplantation are important tools to treat symptomatic (osteo)chondral lesions of the knee joint. However, until now there exists no high-level evidence based accepted rehabilitation plan for the postoperative treatment. HYPOTHESIS/PURPOSE: This survey describes the predominantly used rehabilitation plan as implemented by expert musculoskeletal surgeons for operatively treated (osteo)chondral lesions. STUDY DESIGN: Survey and systematic review. METHODS: An electronic questionnaire covering general and specific items concerning aftercare following cartilage therapy in the knee joint was designed and disposed to analyze rehabilitation programs among a population of expert musculoskeletal surgeons of the AGA (Society of arthroscopy and joint surgery). All instructors (304 in 01/2011) were included into the survey. A total of 246 (80.9 %) instructors answered the questionnaire. RESULTS: The predominant used therapy to treat cartilage lesions is microfracture and for osteochondral lesions the osteochondral transplantation. Physiotherapy starts directly after surgery and takes more than 6 weeks. Most surgeons do not immobilize patients after surgery and use partial weight-bearing for up to 5 weeks. The change from partial to full weight-bearing is done step-wise with a 20-kg/week increase. Free ROM is allowed by the majority of instructors (55 %) directly after surgery. A CPM-device is also used directly and up to 5 weeks. Swimming and biking are allowed after 6 weeks, running is allowed after 12 weeks and contact sports after 24 weeks. Most instructors do not use braces in the aftercare procedure, but nearly all (93 %) prescribe crutches. Typical drugs used during the aftercare are NSAID, Heparin and antibiotics. For most instructors (79 % respectively 75 %) knee stability and a straight leg axis are necessary for a successful cartilage therapy. If a concomitant therapy like ACL reconstruction or an osteotomy is performed, aftercare is mainly dependent on cartilage therapy (62 % respectively 59 % of instructors). CONCLUSIONS: Today there exists no detailed rehabilitation program for treatment after a cartilage-related operation on the basis of an evidence-based level I study. The reason might be that many variables contribute to a specific aftercare procedure. Therefore, the survey of experienced surgeons may help to identify the most promising rehabilitation regime for today, at least until evidence-based level I studies are accomplished.