Matthias Lahner

Arthroscopy vs. MRI for a detailed assessment of cartilage disease in osteoarthritis: diagnostic value of MRI in clinical practice

BackgroundIn patients with osteoarthritis, a detailed assessment of degenerative cartilage disease is important to recommend adequate treatment. Using a representative sample of patients, this study investigated whether MRI is reliable for a detailed cartilage assessment in patients with osteoarthritis of the knee.MethodsIn a cross sectional-study as a part of a retrospective case-control study, 36 patients (mean age 53.1 years) with clinically relevant osteoarthritis received standardized MRI (sag. T1-TSE, cor. STIR-TSE, trans. fat-suppressed PD-TSE, sag. fat-suppressed PD-TSE, Siemens Magnetom Avanto syngo MR B 15) on a 1.5 Tesla unit. Within a maximum of three months later, arthroscopic grading of the articular surfaces was performed. MRI grading by two blinded observers was compared to arthroscopic findings. Diagnostic values as well as intra- and inter-observer values were assessed.ResultsInter-observer agreement between readers 1 and 2 was good (kappa = 0.65) within all compartments. Intra-observer agreement comparing MRI grading to arthroscopic grading showed moderate to good values for readers 1 and 2 (kappa = 0.50 and 0.62, respectively), the poorest being within the patellofemoral joint (kappa = 0.32 and 0.52). Sensitivities were relatively low at all grades, particularly for grade 3 cartilage lesions. A tendency to underestimate cartilage disorders on MR images was not noticed.ConclusionsAccording to our results, the use of MRI for precise grading of the cartilage in osteoarthritis is limited. Even if the practical benefit of MRI in pretreatment diagnostics is unequivocal, a diagnostic arthroscopy is of outstanding value when a grading of the cartilage is crucial for a definitive decision regarding therapeutic options in patients with osteoarthritis.

Prevalence of femoro-acetabular impingement in international competitive track and field athletes

PurposeThe aim of our study was to analyse the prevalence of femoro-acetabular impingement (FAI) in national elite track and field athletes compared to peers using magnetic resonance imaging (MRI) and clinical examination including impingement tests.MethodsA total of 44 participants (22 national elite track and field athletes and 22 non-athletes) underwent an MRI for radiological findings associated with FAI, including alpha angle, lateral centre edge angle (CEA), findings of labral and cartilage lesions. The study group was furthermore investigated by the hip outcome score (HOS) and a clinical hip examination including range of motion (ROM) and impingement tests.ResultsConcerning the cam impingement, there was a significant difference measured by mean alpha angle between the athlete group (52.2 ± 7.29°) and the control group (48.1 ± 5.45°, P = 0.004). Eleven athletes showed a cam impingement, while two probands of the control group had a pincer impingement and one a mixed form (P = 0.0217). There was no statistically significant difference concerning the CEA upon evaluating pincer impingement. Seven track and field athletes had a positive impingement test, whereof three had an increased alpha angle >55°. No participant of the control group showed pathological results in the impingement test (P = 0.0121).ConclusionsMRI evidence and clinical examination suggest that cam impingement is more common in elite athletes in comparison to non-athletes. At a professional level, the intense practice of track and field athletics is susceptible for FAI.

The role of arthroscopy in patients with persistent hip pain after total hip arthroplasty

BACKGROUND Total hip arthroplasty (THA) is a safe and successful procedure for the treatment of osteoarthritis. One of the most common postoperative problems remains persistent hip pain. The arthroscopic evaluation of persistent hip pain following THA can be a valuable diagnostic tool in a select number of patients when carried out by experts in this technique. OBJECTIVE Indication for arthroscopy was persistent pain after THA. Inclusion criteria were an absence of radiological loosening and a sterile aspiration 6 weeks before arthroscopy. Hip joint function and pain were evaluated pre- and postoperatively using the visual analogue scale (VAS) and the Hip Outcome Score (HOS), which scored the activities of daily living (ADL), and a sports subscale. METHODS 5 patients (3 female, 2 male) with an average age of 60.2 ± 4.27 years (range 51-72 years) were included in the study. Arthroscopy with biopsy, adhesiolysis and psoas tendon release was performed 21.0 ± 21.97 months (range 6-57 months) after primary hip replacement. RESULTS Pathological findings were prosthetic joint infection (two cases), impingement between acetabular component and psoas tendon (two cases), adhesions of the periprosthetic tissue (one case). The patients achieved a significant improvement of the Hip Outcome Score (HOS), from an average of 45.6 ± 22.5 (range 14.0-63.1) to 76.5 ± 3.8 (range 41.0-89.4, P=0.016). Evaluation of the VAS showed a significant improvement from a preoperative value of 8.8 ± 0.5 to a postoperative value of 3.4 ± 1.0 (P=0.001). CONCLUSION Hip arthroscopy provides a minimal-invasive tool for diagnosis and therapy. In cases of persistent pain after THA, standard diagnostic procedures should be utilised. Arthroscopy of a hip post-THA would be highly specialised. As a next step, arthroscopy helps the diagnosis and therapy of persistent pain after THA.

Biomechanical and functional indicators in male semiprofessional soccer players with increased hip alpha angles vs. amateur soccer players

BackgroundFemoroacetabular impingement (FAI) is predominant in young male athletes, but not much is known about gait differences in cases of increased hip alpha angles. In our study, the hip alpha angle of Nötzli of soccer players was quantified on the basis of magnetic resonance imaging (MRI) with axial oblique sequences. The aim of the current study was to compare the rearfoot motion and plantar pressure in male semiprofessional soccer players with increased alpha angles to age-matched amateur soccer players.MethodsIn a prospective analysis, male semiprofessional and amateur soccer players had an MRI of the right hip to measure the alpha angle of Nötzli. In a biomechanical laboratory setting, 14 of these participants in each group ran in two shoe conditions. Simultaneously in-shoe pressure distribution, tibial acceleration, and rearfoot motion measurements of the right foot were performed.ResultsIn the semiprofessional soccer group, the mean value of the alpha angle of group was 55.1 ± 6.58° (range 43.2-76.6°) and 51.6 ± 4.43° (range 41.9-58.8°) in the amateur group. In both shoe conditions, we found a significant difference between the two groups concerning the ground reaction forces, tibial acceleration, rearfoot motion and plantar pressure parameters (P < 0.01, P < 0.05, P = 0.04). Maximum rearfoot motion is about 22% lower in the semiprofessional group compared to the amateur group in both shoe conditions.ConclusionsThis study confirmed that semiprofessional soccer players with increased alpha angles showed differences in gait kinematics compared to the amateur group. These findings support the need for a screening program for competitive soccer players. In cases of a conspicuous gait analysis and symptomatic hip pain, FAI must be ruled out by further diagnostic tests.

[Outcome 4 years after isolated single-bundle posterior cruciate ligament reconstruction].

BACKGROUND The purpose of this study was to evaluate the clinical and radiological results after isolated reconstruction of the posterior cruciate ligament (PCL) using semitendinosus (ST) and gracilis (GT) tendon grafts with the arthroscopic single-bundle technique. MATERIALS AND METHODS Following PCL reconstruction using the single-bundle technique performed between 2002 and 2005, 14 patients (2 women, 12 men) prospectively underwent a standardized follow-up examination after an average postoperative time of 4 years. All patients included in this study had isolated insufficiency of the PCL and symptomatic instability. The exclusion criteria were the presence of a complex knee joint instability and the implementation of additional stabilizing measures or another method of PCL reconstructive surgery. The mean follow-up time was 47.2 ± 8.7 months. Preoperative and postoperative stress radiographs were taken using the Telos stress instrument in order to evaluate the posterior translation. Knee joint function and degree of activity were recorded using the Tegner activity score, the subjective IKDC score and the overall IKDC score. RESULTS The posterior tibial translation of 10.1 ± 1.7 mm had an overall average improvement to a postoperative value of 4.6 ± 2.3 mm (p < 0.001). The patients showed a significant improvement in the Tegner activity score from an average 2.7 ± 0.8 points to 5.7 ± 1.3 points (p < 0.001). Evaluation of the subjective IKDC showed a significant improvement from a preoperative score of 41.32 ± 11.23 points to a postoperative score of 65.08 ± 13.51 points (p < 0.001). In total, 10 patients (71.5%) exhibited a normal or nearly normal outcome. According to the objective IKDC score, 4 patients (28.5%) were categorized as moderate. CONCLUSION The above mentioned reconstruction technique can achieve a stable knee function in patients with isolated PCL insufficiency. The isolated single-bundle PCL reconstruction offers a medium-term improvement regarding the activity level and stability of the knee joint.

Reliability of two goniometric methods for measuring active subtalar range of motion

BACKGROUND Measuring subtalar joint (STJ) motion is accompanied by complications due to the oblique STJ axis which results in triplanar pronation and supination. OBJECTIVE We developed a pronator and supinator testing apparatus whose axis was aligned with Inmans STJ axis. The purpose of this study was to assess day-to-day reliability of active STJ range of motion (ROM) measurements and to compare the results with those of a rearfoot goniometer. METHODS Active pronation, supination and total STJ ROM measurements were administered to 12 men (mean age: 23.8 years) and 12 women (mean age: 22.3 years) at two separate test sessions. Intraclass correlations (ICC), limits of agreement (LoA) and minimum detectable change (MDC) were calculated. RESULTS Except for pronation ROM in men, the STJ goniometer revealed substantial (ICC > 0.8) reliability in all conditions. Relative MDCs and LoAs were below 15% and 10%, respectively. Significantly higher total ROM (P< 0.05) was found for women compared to men when using the STJ goniometer. The rearfoot goniometer showed high reliability (ICCs > 0.7) but underestimated STJ ROM in average of 37%. CONCLUSIONS Both goniometric methods showed high day-to-day reliability. However, when using the rearfoot goniometer, researchers have to consider whether the level of underestimation of STJ motion is acceptable in the context of the planned investigation.

Is the Kinect system suitable for evaluation of the hip joint range of motion and as a screening tool for femoroacetabular impingement (FAI)

BACKGROUND In the clinical evaluation of femoroacetabular impingement (FAI), there is a lack of quantitative, reliable and informative assessment methods for the overall functional capability of an individual. OBJECTIVE We compared clinical and radiological measurements of the hip joint with a new methodology based on the concept of 3-dimensional reachable workspace using Microsoft Kinect. METHODS We assessed the correlation between the alpha angle of Nötzli on full-length radiographs and the clinical internal rotation. We evaluated the accuracy of joint positions and angles of the hip between the Kinect system and clinical examination including range of motion (ROM). RESULTS The results of our clinical trial with 24 study participants showed a significant difference between normal internal rotation (> 21°) and reduced internal rotation (⩽ 21°) in comparison to the radiological alpha angle of Nötzli (P=0.026). The acquired reachable Kinect data demonstrated a moderate agreement between the Kinect and clinical examination (correlation coefficients between 0.230 and 0.375). CONCLUSIONS The findings suggest that a higher grade alpha angle of Nötzli accompanies reduced clinical internal rotation. The Kinect system provides reliable results of hip ROM. However, further test series must be performed for the application of Kinect in the clinical evaluation of FAI.

Testing the feasibility and safety of the Nintendo Wii gaming console in orthopedic rehabilitation: a pilot randomized controlled study

Introduction The Nintendo Wii game console is already used as an additional training device for e.g. neurological wards. Still there are limited data available regarding orthopedic rehabilitation. The authors’ objective was to examine whether the Nintendo Wii is an appropriate and safe tool in rehabilitation after orthopedic knee surgery. Material and methods A prospective, randomized, controlled study comparing standard physiotherapy vs. standard physiotherapy plus game console training (Wii group) in patients having anterior cruciate ligament (ACL) repair or knee arthroplasty was conducted. The subjects of the Wii group (n = 17; mean age: 54 ±19 years) performed simple knee exercises daily under the supervision of a physiotherapist in addition to the normal rehabilitation program. The patients of the control group (n = 13; 52 ±18 years) were treated with physiotherapy only. The participants of both groups completed a questionnaire including the International Knee Documentation Committee (IKDC) score, the Modified Cincinnati Rating System and the Tegner Lysholm Knee Score prior to the operation, before discharge from hospital and four weeks after treatment. Results There was no significant difference in the score results between the Wii and the control group (p > 0.05). Conclusions We demonstrated that physiotherapy using the Nintendo Wii gaming console after ACL reconstruction and knee arthroplasty does not negatively influence outcome. Because training with the Wii device was highly accepted by patients, we see an opportunity whereby additional training with a gaming console for a longer period of time could lead to even better results, regarding the training motivation and the outcome after orthopedic surgery.

Development of a functional anatomical subtalar pronator and supinator strength training machine.

BACKGROUND The strength training industry has failed in designing a machine for exercising the pronators and supinators, despite their substantial medio-lateral bracing function. OBJECTIVE The present study documents the muscle strength generation capabilities of the pronators and supinators within their functional anatomic movement plane, using an innovative strength training machine with an oblique axis. METHODS By using two force transducers, the angle-torque relationship of the pronators and supinators of 18 healthy male subjects was identified during maximum voluntary isometric contractions at five anatomical joint angles. Surface EMG was recorded from anterior tibial (TA), peroneus longus (PL) and soleus (SOL) muscles. RESULTS The pronator strength curve showed an inverted U-shaped characteristic, whereas the supinator curve descends from pronated to supinated position. Compared to the muscle activities for one-leg heel raise and toe raise, PL (108-131%) and TA (59-83%), respectively, showed highest activity during pronations. The most activated supinator is SOL (67% of a one-leg heel raise). CONCLUSIONS Differences in the shape of the pronator and supinator strength curves revealed that two different variable cams have to be implemented for matching the human torque capability. We anticipate our study to be a starting point for preventive machine-based training interventions.

Does osteoporosis reduce the primary tilting stability of cementless acetabular cups

BackgroundCementless hip cups need sufficient primary tilting stability to achieve osseointegration. The aim of the study was to assess differences of the primary implant stability in osteoporotic bone and in bone with normal bone density. To assess the influence of different cup designs, two types of threaded and two types of press-fit cups were tested.MethodsThe maximum tilting moment for two different cementless threaded cups and two different cementless press-fit cups was determined in macerated human hip acetabuli with reduced (n=20) and normal bone density (n=20), determined using Q-CT. The tilting moments for each cup were determined five times in the group with reduced bone density and five times in the group with normal bone density, and the respective average values were calculated.ResultsThe mean maximum extrusion force of the threaded cup Zintra was 5670.5 N (max. tilting moment 141.8 Nm) in bone with normal density and.5748.3 N (max. tilting moment 143.7 Nm) in osteoporotic bone. For the Hofer Imhof (HI) threaded cup it was 7681.5 N (192.0 Nm) in bone with normal density and 6828.9 N (max. tilting moment 170.7 Nm) in the group with osteoporotic bone. The mean maximum extrusion force of the macro-textured press-fit cup Metallsockel CL was 3824.6 N (max. tilting moment 95.6 Nm) in bone with normal and 2246.2 N (max. tilting moment 56.2 Nm) in osteoporotic bone. For the Monoblock it was 1303.8 N (max. tilting moment 32.6 Nm) in normal and 1317 N (max. tilting moment 32.9 Nm) in osteoporotic bone. There was no significance. A reduction of the maximum tilting moment in osteoporotic bone of the ESKA press-fit cup Metallsockel CL was noticed.ConclusionResults on macerated bone specimens showed no statistically significant reduction of the maximum tilting moment in specimens with osteoporotic bone density compared to normal bone, neither for threaded nor for the press-fit cups. With the limitation that the results were obtained using macerated bone, we could not detect any restrictions for the clinical indication of the examined cementless cups in osteoporotic bone.