Christoph von Schulze Pellengahr

The cause of subchondral bone cysts in osteoarthrosis: A finite element analysis

Background The etiology of subchondral bone cysts in arthrotic joints is unclear.Materials and methods We used two-dimensional finite element analysis to evaluate the hypothesis that subchondral bone cysts in the osteoarthrotic hip joint may be the result of microfractures caused by localized cartilage defects or a thinned layer of cartilage. We evaluated the equivalent bone stress (von Mises (VM) stress) in the cancellous bone as an indicator of potential microfractures and further development of cystic lesions.Results Cartilage defects induced stress peaks in the subchondral bone. This peak stress distribution corresponded to the clinical observation of development of acetabular and femoral subchondral cysts in a “kissing” position. A femoral subchondral bone cyst induced a stress peak at the corresponding acetabular site, whereas subchondral acetabular cysts did not increase stress in the femoral head. Acetabular cysts showed an increased level of stress at the lateral and medial border of the lesion which was much higher than the stress levels in the femoral head, indicating a tendency to faster growth.Interpretation Our study supports the theory that stress-induced bone resorption may cause development of subchondral bone cysts in osteoarthrosis.

Can serum procalcitonin help to differentiate between septic and nonseptic arthritis

PURPOSE The aim of this study was to evaluate the usefulness of serum procalcitonin (PCT) to differentiate between septic and nonseptic acute arthritis. METHODS Thirty-three patients who presented to our outpatient clinics with the symptoms of acute arthritis of unknown origin were enrolled in this study. We determined the serum concentrations of PCT and C-reactive protein and performed a white blood cell count. The definitive diagnosis was determined by microbiologic examination of a joint aspirate. RESULTS Microbiologic cultures showed that 15 patients had septic arthritis. In these patients the PCT levels were significantly increased compared with those in the 18 patients with nonseptic arthritis (mean +/- SD, 1.18 +/- 1.66 ng/mL v 0.078 +/- 0.073 ng/mL; P = .001). On the basis of the normal range (<0.5 ng/mL), the test sensitivity in our series was 53.3% with a specificity of 100%. C-reactive protein levels in patients with septic arthritis were also significantly elevated compared with the nonseptic group. Because in either group no value was within the normal range (<0.5 mg/dL), the specificity was 0%. CONCLUSIONS In this study serum PCT levels of patients with septic arthritis were significantly higher than those of patients with nonseptic arthritis (P = .001). However, the sensitivity when referencing the normal upper limit of PCT (0.5 ng/mL) is not high enough to establish a diagnosis based exclusively on serum parameters. This reflects the results of other studies examining localized infections without generalized bacteremia. The data suggest that a specific PCT cutoff level for localized infections could be helpful in the future. LEVEL OF EVIDENCE Level III, diagnostic study of nonconsecutive patients without consistently applied reference gold standard.

Medial branch blocks versus pericapsular blocks in selecting patients for percutaneous cryodenervation of lumbar facet joints.

Background and Objectives: At many institutions, it is not practically feasible to perform a series of controlled or placebo-controlled medial branch blocks on several facet joints in order to select patients for facet joint rhizotomy. As for uncontrolled blocks, there is no proof that medial branch blocks are superior to other types of blocks. This study was performed to compare medial branch blocks to simple pericapsular blocks for the selection of patients for lumbar facet joint cryodenervation. Methods: Patient selection was based on history, imaging, and physical examination. Diagnostic blocks were either medial branch blocks or pericapsular blocks. Percutaneous medial branch cryodenervation was performed by use of a Lloyd Neurostat 2000. Outcome parameters were low back pain (visual analog scale [VAS]), limitation of activity (Macnab), and overall satisfaction. A total of 26 patients were recruited, 13 for each group. Follow-up was 6 months. Results: Patients who had been selected by medial branch blocks had better pain relief than did patients who had been diagnosed by use of pericapsular blocks. At 6 weeks and at 3 months after treatment, these results reached statistical significance (VAS 2.2 v 4.2, P < .05). Conclusions: Our results suggest that uncontrolled medial branch blocks are superior to pericapsular blocks in selecting patients for facet joint cryodenervation, but both blocks work. If serial controlled blocks cannot be used, lumbar facet joint pain remains a diagnostic dilemma.

Malignant transformation of a benign enchondroma of the hand to secondary chondrosarcoma with isolated pulmonary metastasis.

Abstract Malignant transformation of solitary enchondromas of the hand to secondary chondrosarcomas is extremely rare. We report a case of a recurrent chondromatous tumor of the hand that initially presented with the typical histology of a cellular enchondroma of the small tubular bones but with clinical and radiological signs of malignancy. After development of a single pulmonary metastasis of a chondromyxoid tumor a malignant transformation of the primary enchondroma of the hand must be assumed.

Long-Term Results of High Tibial Osteotomy for Medial Osteoarthritis of the Knee

Abstract We reviewed retrospectively the results in patients who had undergone one hundred and four high tibial lateral osteotomies. The operations were all performed between 1985 and l993. Each one of fifty men and forty nine women demonstrated a varus deformity of the knee with a coexistent medial osteoarthritis. Results were reviewed in 49 patients (62 knees) with an average follow-up of 10.2 years (range 6-14 years). Of the remaining 42 patients, 8 were lost to follow-up, l0 had died, and 24 were subsequently treated with total knee arthroplasty at an average 4.7 years after having had a high tibial osteotomy. Clinical results were evaluated using the Hospital for Special Surgery Score (HSS) and the Knee Society Score. Radiographs were systematically analysed to evaluate osteoarthritis and leg axis. Forty four (90 per cent) of the forty nine patients stated the results met their expectations and given the same circumstances, they would have the operation once again. In these patients the knee score results were excellent. The same patients had excellent HSS and Knee Society Scores. Five patients (10 per cent) had a poor result and twenty four patients were treated later by total knee arthroplasty because of pain. The following factors set these patients apart from those with more favorable results: previous arthroscopic debridement, obesity, lateral knee osteoarthritis, insufficient valgus correction, and an age of more than 55 years. High tibial valgus osteotomy provides good pain relief and improved function in carefully selected patients. Our results support this conclusion.

Die Metall-Metall-Paarungen für den künstlichen Hüftgelenkersatz

ZusammenfassungDie 1.Generation der Metall-Metall-Paarungen hat aufgrund von Fertigungsmängeln aber auch wegen Werkstoffproblemen nicht den Anforderungen entsprochen.Da sehr viele unbefriedigende klinische Ergebnisse zu verzeichnen waren,wurde die “1.Generation” schnell wieder verlassen.Unabhängig davon zeigten sich jedoch vereinzelt Fälle mit sehr guten Langzeitergebnissen,was dazu geführt hat, dass diese Metall-Metall-Paarung eine Renaissance erleben durfte.Diese Renaissance ging sowohl mit einer Verbesserung der Fertigungstechnologie einherging,aber auch mit einer Verwendung von besseren Materialien.Die 2.Generation,die insbesondere unter dem Markennamen METASUL® bzw.SIKOMET®bekanntwurden,ist zwischenzeitlich ca.10 Jahre im klinischen Einsatz.Die in Simulatorversuchen sich als günstig erwiesenen Ergebnisse beginnen sich auch in der Klinik durchzusetzen.Ein Problem haben die neuen Gleitpaarungen mit Metall-Metall insofern, als sie nach einer gewissen Einlaufphase sehr große Mengen an submikroskopisch kleinen Partikeln erzeugen.Diese submikroskopischen Partikel haben sehr große Oberflächen, wobei die Interaktion zwischen Körpermilieu und Metallpartikel zu allergologisch-toxischen Problemen führen könnte. Der Beweis dafür steht noch aus.Neben der Beschreibung der tribologischen Probleme finden sich auch Überlegungen zur entzündlichen Gewebereaktion auf Abriebpartikel, die möglicherweise bei der Metall-Metall-Paarung eine besondere Rolle spielen.AbstractDue to engineering deficiencies as well as problems in the basic material, the first generation of metal-on-metal hip prostheses was not up to standard.Furthermore, unsatisfying clinical results led to a decrease in the use of these prostheses.Nevertheless, there were several cases which demonstrated good results in long-term clinical outcome. After distinct improvements in manufacturing and materials, metal-on-metal prostheses have made a come back.This second generation, which are known mainly under the names METASUL and SIKOMET,have been in clinical use for up to 10 years and the good results found in biomechanical set ups seem to be confirmed in clinical trials.However, a possible disadvantage of this second generation of metal-on-metal hip prostheses might be the production of large amounts of particulate wear debris in the nanometer size range.Whether the great number of small size particles with an extended metal surface and the possible distribution of these particles in the body have biological effects on the cells and tissues (such as allergic or toxic reactions) remains unknown. Among the tribological problems , there is currently a discussion on the possible inflammatory effect of these metal particles, which might play a crucial role in longterm, systemic reactions of the body to metal particles.

Sympathetic dysfunction in long-term complex regional pain syndrome.

ObjectiveMalfunction of the sympathetic nervous system (SNS) is common in early complex regional pain syndrome type I (CRPS I). This study was designed to evaluate the function of the SNS in patients with chronic CRPS I and to correlate the obtained data with hand function measurements. Materials and MethodsThirty-two patients of both the sexes in whom the diagnosis of CRPS I of the upper extremity had been established for at least 3 years before they were included in the study. Besides a hand outcomes questionnaire [Michigan Hand Outcome Questionnaire, (MHQ)] the patients underwent a standardized testing of the peripheral sympathetic nervous system (pSNS) using laser Doppler flowmetry (LDF). ResultsMean time since initial diagnosis was 4.6±2.1 years. The mean MHQ score of the affected limb was 57.3±17 compared with 69.4±13.7 for the unaffected hand (P=0.002). Twenty patients (62.5%) still demonstrated pathologic results regarding the pSNS function (mean sympathetic reflex 0.18±0.11, normal range>0.38). We found no statistically significant correlation between pSNS function either with the clinical outcome as measured by MHQ (r=0.246; P=0.175), or with the level of pain (r=0.132; P=0.473). ConclusionsEven 5 years after the diagnosis of CRPS I of the upper extremity we detected significant impairments of the pSNS in nearly two thirds of our patients. Patients still have pain and present with a significant deterioration of their hand function in comparison with the not affected hand. In our study we could not identify any correlation between pSNS function and clinical outcome as measured by MHQ.

Spinal cord infarction after operative stabilisation of the thoracic spine in a patient with tuberculous spondylodiscitis and sickle cell trait.

Study Design. Case report. Objective. To describe and discuss the case of a patient, later recognized to have sickle cell trait (SCT), who suffered from tuberculous spondylodiscitis and developed a spinal ischemia after spinal decompression and stabilization and to discuss the literature on this. Summary of Background Data. Spinal ischemia is a rare event and even more unusual after spinal surgery. Vaso-occlusive complications like strokes occur in patients with sickle cell disease, but spinal ischemia has rarely been reported. SCT is generally seen as a benign disorder with vaso-occlusive complications having been described under extreme conditions. Methods. We report the case of a 39-year-old woman, born in Togo and living in Germany for more than 11 years, who presented to our outpatient clinics with a tuberculous spondylodiscitis. She underwent a dorsal decompression and pedicle screw instrumentation from T7–T11. Results. A few hours after surgery, the patient developed an acute paraplegia of the lower extremities, which accentuated on the left side combined with urinary incontinence and anal sphincter dysfunction but without sensory deficits of the lower extremities. A CT-scan and a second-look surgery revealed no cause for the symptoms. A magnetic resonance imaging showed that the patient had suffered spinal ischemia worst at the T4 level. On further investigation she was noted to have SCT. Conclusion. We assume that the combination of the patient’s SCT status and the physiologic stress of surgery likely explain this patient’s spinal ischemia.

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.

Acute paraplegia after vertebroplasty caused by epidural hemorrhage : A case report

Vertebroplasty is widely used for the palliative stabilization of osteoporotic fractures and vertebral metastases. Serious complications with this procedure are rare and, as a result, vertebroplasty is being performed increasingly in hospitals without a spinal surgery unit or even in radiology practices where such complications may not be managed adequately when they arise. The leakage of cement into draining veins is the most frequent complication1,2, followed by cement penetration into the spinal canal. Fatal pulmonary embolism has been reported, and small cement emboli are not uncommon1,3. When cement penetration into the spinal canal causes a neurological deficit, decompression and often removal of the cement are required. The case of a patient who had an epidural hematoma after kyphoplasty associated with the postoperative administration of an intravenous heparin bolus has been described4. We report the case of a patient who had an acute epidural hemorrhage causing paraplegia as a complication from vertebroplasty. To the best of our knowledge, this is the first such report. The patient was informed that data concerning the case would be submitted for publication. An eighty-two-year-old woman with intractable back pain was transferred to our service from another hospital. A diagnosis of osteoporosis had been made following multiple vertebral fractures that had occurred approximately one year before and from which she had fully recovered after treatment with oral analgesics, calcium, vitamin D, and use of a brace. When renewed back pain developed, she first had received outpatient therapy with a variety of orally administered analgesics, including opioids for about five weeks, and oral alendronate (70 mg once per week). At the time of transfer to our department, she was receiving high doses of narcotic analgesics both orally and intravenously, but she was still immobilized because of pain. …