Christian Bach

Intrapelvic complications after total hip arthroplasty failure

BACKGROUNDnSevere total hip arthroplasty failure with central migration of prosthetic components is uncommon. If perforation of the medial acetabular wall occurs, injuries of intrapelvic structures may result.nnnDATA SOURCESnA meta-analysis of the English literature was performed. A human pelvic cadaver was used to demonstrate the proximity of intrapelvic structures to a centrally dislocated cup.nnnRESULTSnFifty cases of intrapelvic injury were identified. Structures involved most frequently were the external iliac artery and the bladder. The most common types of complication included fistula formation, development of a false aneurysm, and hemorrhage. The human cadaver pelvis demonstrated the proximity of intrapelvic vessels, the bladder, the ureter, the vagina, the deferent duct, the sigmoid colon, the rectum, and the sciatic nerve to an intrapelvically intruded prosthesis.nnnCONCLUSIONSnFailed total hip replacements should be considered to cause damage to pelvic viscera.

Patella resurfacing: no benefit for the long-term outcome of total knee arthroplasty

Abstract. A follow-up of more than 10xa0years among patients who have undergone a total knee arthroplasty (TKA) was performed to determine the significance of patella resurfacing for the long-term outcome. The clinical outcome was assessed by the Knee Society Score (KSS), and the radiological outcome was determined based on the Knee Society Roentgenographic Evaluation System. The patella was preserved in 21 knees and resurfaced in 44 knees. The mean follow-up time was 11.6xa0years (range 10–16.3xa0years). There was no significant difference in the clinical outcome between the knees with patella resurfacing (knee points: mean 85.3 ±12.9, function points: mean 70.3 ±23.4) and the knees with patella retention (knee points: mean 82.7 ±16.2, function points: mean 71.7 ±22.4; p=0.58 for knee, and p=0.83 for function points). There was also no significant difference in the radiological outcomes regarding the angles α, β, ϒ, δ, and valgus (p>0.05 for each variable). There was, however, a trend towards more lucencies in TKAs with a resurfaced patella on the tibia side in the anteroposterior view (p=0.052). Patellar complications were found more often in the resurfaced group (20.5%) than in the group without resurfacing (9.6%). The results indicate overall no advantage of patella resurfacing compared with patella retention in the long run.

No functional impairment after Robodoc total hip arthroplasty

The Robodoc total hip replacement procedure requires a wider exposure of the proximal femur, especially of the greater trochanter, than the standard procedure. Moreover, the leg must be placed in a rigid leg-holder apparatus to obtain fixation in maximal hip adduction and external rotation. This may impair the hip abductors and reduce hip abduction in the mid- and terminal stance phase of the cycle. In this study we compared patients after Robodoc and conventional total hip arthroplasty with three-dimensional gait analysis (VICON System, Oxford Metrics, Oxford, U.K.) to assess the kinematics of the pelvis and hip. 25 patients underwent total hip replacement by means of the Robodoc total hip arthroplasty system, 25 patients were treated with conventional total hip replacement, and 40 healthy volunteers served as controls. None of the patients undergoing total hip replacement, robotic or conventional, obtained normal kinematic gait patterns 6 months after surgery. However, the reduction in hip abduction did not differ significantly in patients undergoing robotic or conventional total hip arthroplasty, which suggests that the robotic procedure did not impair hip abductor function more than the conventional method. n

High-Dose-Rate Intraoperative Brachytherapy (IOHDR) Using Flab Technique in the Treatment of Soft Tissue Sarcomas

Background: Adjuvant radiotherapy has been shown to improve local control in patients with soft tissue sarcoma. Additional brachytherapy represents a means of enhancing the therapeutic ratio, as biological and dosimetric advantage over single external-beam irradiation (EBRT) can be expected. High-dose-rate intraoperative brachytherapy (IOHDR) as a boost therapy should therefore be able to further diminish the rate of local recurrence even when performing marginal resection. There are sparse data on IOHDR using flab applicators as adjuvant boost to EBRT in combination with marginal resection of soft tissue sarcomas.nPatients and Methods: Within a period of 8 years, we prospectively studied 39 adult patients treated by marginal resection, IOHDR using the flab technique and EBRT for soft tissue sarcomas. There were 32 high-grade and seven low-grade tumors, 35 were > 5 cm. Mean follow-up was 26 months (range 3–59 months).nResults: We could not detect any local recurrences. No treatment-related loss of limb or life occurred. There were no neurologic or vascular complications, all patients maintained functioning extremities as evidenced by a mean Musculoskeletal Tumor Society (MSTS) functional score of 88.5 (70–100). Treatment-related wound morbidity occurred in eleven patients necessitating revision surgery in eight. Metastatic disease developed in seven patients, six of them had died. The 2-year actuarial disease-free survival was 84%.nConclusions: IOHDR using the flab technique in combination with EBRT and marginal resection is an efficient treatment technique leading to optimal local control rates and limited functional impairment.Hintergrund: Die adjuvante perkutane Strahlentherapie hat unter Beweis gestellt, dass sie die lokale Kontrolle von Weichteilsarkomen verbessern kann. Eine zusätzliche Brachytherapie könnte die therapeutische Wirksamkeit weiter erhöhen, da mit einem biologischen und dosimetrischen Vorteil gegenüber der alleinigen perkutanen Strahlentherapie zu rechnen ist. Die intraoperative Hochdosisbrachytherapie (IOHDR) als Boost-Therapie sollte daher in der Lage sein, die Lokalrezidivrate weiter zu senken, selbst wenn der Tumor nur marginal reseziert wird. Bis jetzt gibt es nur sehr wenige Daten über die IOHDR unter Verwendung von Flab-Applikatoren und marginaler Resektion von Weichteilsarkomen.nPatienten und Methodik: Innerhalb einer Zeitspanne von 8 Jahren haben wir prospektiv den Verlauf von 39 erwachsenen Patienten verfolgt, die wegen eines Weichteilsarkoms mit marginaler Tumorresektion, IOHDR unter Verwendung von Flab-Applikatoren und perkutaner Strahlentherapie behandelt wurden. Es lagen 32 hochmaligne und sieben niedrigmaligne Tumoren vor, 35 Tumoren waren > 5 cm. Die mittlere Nachuntersuchungszeit betrug 26 Monate (3–59 Monate).nErgebnisse: Es ließen sich keine Lokalrezidive feststellen. Auch kam es zu keinem Extremitätenverlust oder therapiebedingten Todesfällen. Es traten keine Nerven- oder Gefäßkomplikationen auf, bei allen Patienten konnten funktionstüchtige Extremitäten erhalten werden, was sich in einem mittleren Musculoskeletal-Tumor-Society-(MSTS-)Funktionswert von 88,5 (70–100) zeigte. Wundheilungsstörungen stellten sich bei elf Patienten ein, die aber nur in acht Fällen chirurgisch versorgt werden mussten. Fernmetastasen traten bei sieben Patienten auf, von denen in der Zwischenzeit sechs verstorben sind. Die aktuarische krankheitsfreie 2-Jahres-Überlebensrate betrug 84%.nSchlussfolgerungen: Die IOHDR in Verbindung mit perkutaner Strahlentherapie und marginaler Tumorresektion stellt eine effektive Behandlungstechnik dar, die den Tumor lokal optimal kontrolliert und die Extremitätenfunktion nur geringfügig einschränkt.

Excessive heat generation during cutting of cement in the Robodoc hip-revision procedure

The ROBODOC system is a promising new method for removing cement with high-speed milling. Heat is generated during the milling process. This study was designed to measure temperatures in the cutting area, and to assess the risk of heat injury and the effectiveness of irrigation. We measured temperatures at the bone-cement cutting area in three experimental settings, two involving the proximal area comprising a cement mantle, and one the distal cement plug beneath the prosthesis. Without cooling facilities, a mean temperature of 94 °C was measured in proximal areas. However, this could effectively be reduced below 70 °C with irrigation. In the area of the distal cement plug, we measured a mean temperature of 172 °C without irrigation. In this area, the integrated irrigation system with an additional high-flow irrigation system could not guarantee cooling to an acceptable temperature of below 70 °C since the irrigation stream was impeded by the cutter in the narrow cavity. We need an integrated irrigation device that guarantees continuous cooling at the cutting interface in front of the cutter.

Radiographic evaluation of cervical spine trauma. Plain radiography and conventional tomography versus computed tomography.

Abstract Different imaging modalities are available for the diagnosis of cervical spine injuries. There is a controversial discussion about whether plain radiography (PR), conventional tomography (CTO) or computed tomography (CT) should primarily be used. PR and CTO are more often available and less costly than CT. Especially in second-care hospitals, CT is not always available. The diagnostic work-up in these centres has to rely on conventional techniques. The aim of this study was to define the role of PR supplemented by CTO in the diagnosis of cervical spine trauma in comparison to CT. Twenty-five patients were identified who underwent plain radiography (PR), conventional tomography (CTO) and computed tomography (CT) for the diagnosis of a cervical fracture. In 19 patients a fracture of the cervical spine was identified. All images were reviewed by two independent observers to estimate the interobserver variability. The highest detection rate was achieved by CT (18/18 fractures detected for observer 1/2), followed by CTO (16/16 fractures) and then PR (15/14 fractures). When the detection rates of PR and CTO are combined, 18 fractures were detected by each of the observers. The results were analysed for the dens and the rest of the cervical spine independently. For PR and CTO the detection rates were lower for fractures of the dens than for the rest of the cervical spine. We conclude that the combination of PR and CTO accurately detects fractures of the cervical spine compared with CT. If a fracture of the dens is suspected, the patients should be referred to CT due to its superior accuracy in this region.

Multisegmental pneumatocysts of the lumbar spine mimic osteolytic lesions.

Abstract Circumscribed radiolucencies within the vertebral bones can be due to a variety of changes including benign and malignant tumours or tumour-like lesions. Radiolucencies due to degenerative intraosseous pneumatocyst are very uncommon but have to be taken into the differential diagnosis in well-circumscribed lytic lesions of the vertebral bodies. We describe the first case of multisegmental pneumatocysts in the lumbar spine mimicking osteolytic lesions. On computed tomography, the air-equivalent attenuation values of the lesions and the close vicinity to the degenerated vertebral endplates with vacuum phenomenon led to the correct diagnosis.

Aerosols produced by high-speed cutters in cervical spine surgery: extent of environmental contamination

Abstract. High-speed cutters are used in the surgery of the cervical spine. Such high-speed devices can produce an aerosol cloud. As a patient can be a reservoir for pathogens, with aerosol-borne paths of transmission, such an aerosol has to be seen as a potential risk of infection for health care professionals present during the surgery and for patients if micro-organisms are transferred through the medical personnel. The study was performed in order to measure the extension of environmental and body contamination through contaminated aerosols produced by a high-speed cutter. Three laminectomies (C4–C6) were performed on an intact human cadaver with a high-speed 0.6-mm ball cutter. A complete surgical setup was arranged, including surgical draping and a barrier drape to the anesthesiologists workplace. Body and environmental contamination was detected by the use of surveillance cultures. The irrigation solution was artificially contaminated with Staphylococcus aureus ATCC 12600. Following the surgery, staphylococci were detected in the operating room at an extension of 5×7xa0m. Everybody showed extensive face and body contamination with Staphylococcus aureus. The study showed that the use of high-speed cutters in surgery of the cervical spine produces an aerosol cloud that is spread over the whole surgical room and contaminates the theater and all personnel present. Such aerosols can be contaminated with pathogens if the patient was infected or colonized. Therefore, sufficient protective measures have to be recommended for everyone present in the operating room during such surgeries. In addition, efficient disinfection of the room and all mobile equipment is necessary after each surgery involving high-speed cutting devices.

Assessment of Talar Flattening in Adult Idiopathic Clubfoot

Background: The radius/length (R/L) ratio was developed to evaluate the convexity of the talar dome in idiopathic clubfoot. However, the index has not been tested for its reliability and reproducibility. Methods: The R/L ratio was determined by three independent observers on the radiographs of 21 adult patients with idiopathic clubfoot and 30 adult subjects with normal feet. The reproducibility and the reliability of the R/L ratio were calculated. Results: For the normal feet the reproducibility and the reliability of the R/L ratio was high (correlation coefficient > 0.87). For the patients with clubfoot, the reliability and reproducibility depended on the severity of talar flattening. For a radius of less than 45 mm the mean intraobserver correlation coefficient was 0.74 (range 0.54 to 0.83) and the mean interobserver correlation coefficient was 0.58 (range 0.49 to 0.75). For a radius of more than 45 mm no statistically significant intraobserver and interobserver correlations were found. Conclusion: The current results indicate that the R/L ratio of talar flattening is reliable and reproducible for mild talar deformity but not for severe flattening (radius of more than 45 mm).

Hematuria due to an intrapelvically intruding total hip replacement.

A 92 year old male patient was referred to our service because of gross hematuria. He had a history of numerous episodes of hematuria in the last year. A cystoscopy was performed as first measure. The bladder neck, the trigone and the ureteral orifices were normal. Inspection of the mucosa revealed a localized bleeding area three centimeter in diameter within the posterior wall of the bladder. This area was bulged by an extravesical solid tumor of unknown etiology. Local pressure had caused central necrosis, but no fistula could be observed. Plain radiographs of the pelvis were performed revealing severe osteolytic destruction of the right acetabulum, a proximal fracture of the right superior pubic ramus and central transpelvic dislocation of the prosthetic stem of a total hip replacement with the femoral head supporting at the contralateral sacroiliac joint (Figure 1). A computed tomography was performed demonstrating extravesical compression due to the dislocated prosthetic stem (Figure 3). Medical records revealed that the patient underwent total hip arthroplasty 22 years ago. Failure of the implant was reported but revision surgery was not performed. Revision surgery including removal of the intrapelvic prosthesis was initiated to avoid bladder rupture. Extraction of the stem was performed successfully, the patient recovered well and no further events of hematuria were recorded.