Rupture of the spleen following thoracoscopic spine surgery in a patient with chronic pancreatitis

Purpose

To highlight the perioperative risk of intracapsular haematoma of the spleen or splenic ruptures during thoracoscopic spine surgery in patients with chronic pancreatitis.

Methods

A 38-year-old patient with an L1 burst fracture (AO A3.3) underwent a standard thoracoscopic corpectomy and replacement of the vertebral body with an extendable vertebral body replacement 10 days after posterior instrumentation of T12–L2. In patients history chronic abusive alcoholism with related diseases such as pancreatitis, followed by hemipancreatectomy was found. Six hours after the surgery, the patient became hemodynamically unstable. An emergency CT scan revealed a splenic rupture. Emergent splenectomy was performed.

Results

After surgical treatment of the L1 burst fracture, a rupture of the spleen was detected. An immediate splenectomy was performed. At the 18-month follow-up, an unchanged stable position of the cage was observed on CT.

Conclusions

Due to its proximity to the thoracolumbar junction, the spleen is vulnerable to injury during spine surgery. If the patient has undergone previous intra-abdominal operations or chronic inflammation of the pancreas is found, special care of the spleen during the operation is necessary.

     

Rupture of the spleen following thoracoscopic spine surgery in a patient with chronic pancreatitis

Purpose

To highlight the perioperative risk of intracapsular haematoma of the spleen or splenic ruptures during thoracoscopic spine surgery in patients with chronic pancreatitis.

Methods

A 38-year-old patient with an L1 burst fracture (AO A3.3) underwent a standard thoracoscopic corpectomy and replacement of the vertebral body with an extendable vertebral body replacement 10 days after posterior instrumentation of T12–L2. In patients history chronic abusive alcoholism with related diseases such as pancreatitis, followed by hemipancreatectomy was found. Six hours after the surgery, the patient became hemodynamically unstable. An emergency CT scan revealed a splenic rupture. Emergent splenectomy was performed.

Results

After surgical treatment of the L1 burst fracture, a rupture of the spleen was detected. An immediate splenectomy was performed. At the 18-month follow-up, an unchanged stable position of the cage was observed on CT.

Conclusions

Due to its proximity to the thoracolumbar junction, the spleen is vulnerable to injury during spine surgery. If the patient has undergone previous intra-abdominal operations or chronic inflammation of the pancreas is found, special care of the spleen during the operation is necessary.

     

Treatment strategies for infection after reverse shoulder arthroplasty

Introduction

Infection after reverse shoulder arthroplasty (RSA) is a disastrous complication. No clear guidelines describing specific management strategies for infection after RSA are available.

Methods

We retrospectively analyzed 20 patients treated for deep infection after RSA. Initial irrigation and debridement and exchange of the polyethylene inlay were performed in seven patients, and initial two-stage revision was performed in 12 and initial resection arthroplasty in one patient. Patient charts were reviewed for risk factors, clinical symptoms and investigations of those symptoms, pre- and postoperative X-rays, interval until revision surgery, causative bacteria, complications, final clinical outcome and patient satisfaction.

Results

The mean overall postoperative Constant–Murley Score (CMS) was 42.6 points, the mean UCLA score was 20.8, the mean simple shoulder test (SST) was 5.5, and the mean VAS was 1.5. When comparing the CMS, UCLA score and the SST between the revision RSA group and the resection group, significant differences between the groups were found (p < 0.05). Irrigation, debridement and exchange of the polyethylene inlay were successful only in two of the four patients with acute infection. The three patients with subacute infections were treated with initial irrigation and debridement and exchange of the polyethylene inlay, which were not successful.

Conclusion

The relatively high patient satisfaction can be explained by the low pain level once the patient is free from infection. However, functional results are poor in most cases, and this possible outcome must be discussed with the patient in the preoperative setting.     

Temporal bone borehole accuracy for cochlear implantation influenced by drilling strategy: an in vitro study

Purpose

Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources.

Methods

The experimental setup to evaluate the borehole accuracy comprises a drill handpiece attached to a linear slide as well as a highly accurate coordinate measuring machine (CMM). Based on the specific requirements of the minimally invasive cochlear access, three drilling strategies, mainly characterized by different drill tools, are derived. The strategies are evaluated by drilling into synthetic temporal bone substitutes containing air-filled cavities to simulate mastoid cells. Deviations from the desired drill trajectories are determined based on measurements using the CMM.

Results

Using the experimental setup, a total of 144 holes were drilled for accuracy evaluation. Errors resulting from the drilling process depend on the specific geometry of the tool as well as the angle at which the drill contacts the bone surface. Furthermore, there is a risk of the drill bit deflecting due to synthetic mastoid cells.

Conclusions

A single-flute gun drill combined with a pilot drill of the same diameter provided the best results for simulated minimally invasive cochlear implantation, based on an experimental method that may be used for testing further drilling process improvements.     

Improvement of local control by regional hyperthermia combined with systemic chemotherapy (ifosfamide plus etoposide) in advanced sarcomas: updated report on 65 patients

From July 1986 to 1990, 65 patients with deepseated, advanced sarcomas (43 soft-tissue sarcomas, 12 Ewing's sarcomas, 7 chondrosarcomas and 3 osteosarcomas) were entered in a protocol involving regional hyperthermia (RHT) combined with systemic ifosfamide and etoposide. RHT was produced by an electromagnetic deep regional heating device (BSD Medical Corporation, Salt Lake City, Utah). Of these patients, 62% (40 patients) had received ifosfamide-containing drug regimens before entering the RHT study, 26% (17 patients) were pretreated by surgery and/or radiation and 12% (8 patients) were treated primarily. A total of 426 RHT treatments (mean 6.6 RHT/patient) were applied predominantly within the pelvic region (82%) bearing relative large tumours (mean volume 500 cm³). For systemic chemotherapy, all patients received ifosfamide (1.5 g/m², days 1–5), etoposide (100 mg/m², days 1, 3, 5) and 2-mercaptoethanesulphonic acid (mesna; 300 mg/m²×4, days 1–5) with RHT only given on days 1 and 5 in repeated cycles every 4 weeks. Detailed thermal mapping by invasive thermometry was performed in all patients. In 61 patients evaluable for tumour control the overall objective response rate including 9 complete responders (CR), 4 partial responders (PR) and 8 patients with favourable histological response (FHR) was 34% (95% confidence limits, 23%–46%). Following CR, the patients are alive and remain disease-free (mean disease-free survival 15.6 months). Of the patients with PR and FHR, 3 died from metastatic and/or local disease after 4, 17, and 39 months, and 1 patient died from other disease (acute myelocytic leukemia) after 27 months. The other 8 patients remain stable at 29, 25, 17, 11, 10, 8, 7, and 6 months. Twenty-two patients revealed no change and 18 patients showed local tumour progression (PD). Side-effects of RHT were tolerable and there was no indication of enhanced bone marrow toxicity due to the addition of RHT to the systemic chemotherapy. By analysis of temperature parameters, the time-averaged temperatures of all RHT treatments calculated for 20% (T ₂₀), 50% (T ₅₀) or 90% (T ₉₀) of measured tumour sites differed significantly between responders (CR+PR+FHR) and non-responders (PD), respectively (T ₂₀,P=0.001;T ₅₀,P= 0.0005;T ₉₀,P=0.0001). The data further support a strong potential for ifosfamide plus etoposide combined with RHT in pretreated patients with advanced sarcomas.Presented at the Satellite Symposium Ifosfamide in Tumor Therapy: Questions for the Nineties; 15th International Cancer Congress, Hamburg, August 16–22, 1990     

Configuration optimization and experimental accuracy evaluation of a bone-attached,parallel robot for skull surgery

Purpose

Minimally invasive cochlear implantation is a novel surgical technique which requires highly accurate guidance of a drilling tool along a trajectory from the mastoid surface toward the basal turn of the cochlea. The authors propose a passive, reconfigurable, parallel robot which can be directly attached to bone anchors implanted in a patient’s skull, avoiding the need for surgical tracking systems. Prior to clinical trials, methods are necessary to patient specifically optimize the configuration of the mechanism with respect to accuracy and stability. Furthermore, the achievable accuracy has to be determined experimentally.

Methods

A comprehensive error model of the proposed mechanism is established, taking into account all relevant error sources identified in previous studies. Two optimization criteria to exploit the given task redundancy and reconfigurability of the passive robot are derived from the model. The achievable accuracy of the optimized robot configurations is first estimated with the help of a Monte Carlo simulation approach and finally evaluated in drilling experiments using synthetic temporal bone specimen.

Results

Experimental results demonstrate that the bone-attached mechanism exhibits a mean targeting accuracy of \((0.36\pm 0.12)\) mm under realistic conditions. A systematic targeting error is observed, which indicates that accurate identification of the passive robot’s kinematic parameters could further reduce deviations from planned drill trajectories.

Conclusion

The accuracy of the proposed mechanism demonstrates its suitability for minimally invasive cochlear implantation. Future work will focus on further evaluation experiments on temporal bone specimen.

     

Joint-preserving treatment for type 3 sequelae following fracture of the proximal humerus with small head fragments

BackgroundAlthough nonunions of the proximal humerus are rare, they cause significant disability to patients. Surgical reconstruction is challenging, especially with small and excavated head fragments. A promising surgical option is open reduction and stabilization using the Humerusblock device along with tension wires. The aim of this retrospective investigation was to evaluate the clinical and radiological results of this procedure.Materials and methodsFifteen patients with symptomatic surgical neck nonunions were treated with open reduction and internal fixation using the Humerusblock device without bone grafting. All patients showed a loss of bone stock, leading to excavated head fragments. The mean interval from injury to the described treatment was 6.2 months (range, 3.4–10.7). At a mean follow-up of 40.5 months, the Constant-Murley score was documented, pain and patient satisfaction were evaluated using a visual analogue scale, and x-rays were taken in two planes.ResultsThe patients’ mean age was 69.7 years (range, 52–83). The mean Constant-Murley score improved from 24 points before surgery to 62 points at follow-up, which was an average of 80.8% of the score obtained for the contralateral arm. Radiological examination confirmed bony healing in 14 patients. All but one patient felt satisfied with the results. Three patients required revision surgery because of a hematoma, and early metal removal was performed in one patient because of infection.ConclusionNonunions of humeral surgical neck fractures can be successfully treated by fixation using the Humerusblock device along with tension wires without the need for additional bone grafting. Especially in patients with flat, concave head fragments, this procedure remains a promising reconstructive option to arthroplasty.Level of EvidenceLevel IV; Therapeutic retrospective case series.     

Reference values for fatigued versus non-fatigued limb symmetry index measured by a newly designed single-leg hop test battery in healthy subjects: a pilot study

Purpose

There is sparse evidence for return to sport criteria after knee injury. Functional performance deficits, particularly in fatigued muscular condition, should be verified prior to the attempt to return to high-risk pivoting sports. The purpose of this study was to generate reference values for the limb symmetry index (LSI) of healthy subjects in fatigued and non-fatigued muscular condition in a newly designed test battery.

Methods

Forty-two healthy subjects [22 females, 20 males; mean (SD) age 30.4 (6.6) years] were evaluated using a test battery consisting of an isometric strength test, a series of five single-leg hop tests and an integrated fatigue protocol. Subjective physical activity was assessed with the Tegner Activity Scale (TAS). The cut-off values for healthy subjects were calculated considering the fifth percentile as the minimum reference value for the LSI and single-leg hop distance.

Results

The mean (SD) overall LSI was 98.8% (4.6). No significant gender or age specific differences in limb symmetry were observed. The comparison of the non-fatigued LSI with the overall LSI revealed no clinically relevant change due to muscular fatigue. Repeated measures ANOVA revealed a significant within effect on fatigue/non-fatigue condition (F _(1,38) = 18.000; p < 0.001, η ² = 0.321) on absolute single-leg hop distance. Moreover, a significant between effect on the TAS-parameter (F _(1,38) = 5.928; p = 0.020, η ² = 0.135 between: TAS ≤ 5/TAS > 5) and on gender (F _(1,38) = 23.956; p < 0.001, η ² = 0.387) could be detected.

Conclusions

The absolute jumping distance in the single-leg hop for distance was significantly reduced due to fatigue. No clinically relevant effect of muscular fatigue was observed on limb symmetry in our study sample. Gender and physical activity are important factors to be considered when interpreting reference values.

     

Assessment of atlantoaxial rotation: how accurate is clinical measurement? a comparative study of cervical range of motion using MRI and standard orthopedic techniques

Purpose

Measurement of neck rotation is currently reliant on radiologic imaging. Given the radiation exposure for CT imaging and the additional inconvenience for the patients, an alternative assessment is needed. Goniometers are comfortably to use and easy to access, also for private consulting. The aim of this study was the assessment of whether a handheld goniometer can be used for accurately measuring the rotation of C1-C2.

Methods

Clinical measurement of rotation was taken in flexed position of the neck. As comparison functional MRI was used. The measured rotation of C1-C2 was compared to identify the accuracy of the goniometer, in comparison to functional MRI scan.

Results

Analysis of accuracy using a goniometer and dynamic MRI to assess C1-2 axial rotation showed significant differences for absolute values, but not regarding the percentage of rotation compared to total neck rotation.

Conclusion

The goniometer is exact to impartially determine the percentage contribution of C1-2 rotation to total neck rotation.

     

Reverse shoulder arthroplasty in revision of failed shoulder arthroplasty—outcome and follow-up

Purpose

The number of shoulder arthroplasties has increased over the last decade, which can partly be explained by the increasing use of the reverse total shoulder arthroplasty technique. However, the options for revision surgery after primary arthroplasty are limited in cases of irreparable rotator cuff deficiency, and tuberosity malunion, nonunion, or resorption. Often, conversion to a reverse design is the only suitable solution. We analysed the functional outcome, complication rate and patient satisfaction after the revision of primary shoulder arthroplasty using an inverse design.

Methods

Over a ten-year period 57 patients underwent revision surgery for failed primary shoulder arthroplasty using a reverse design. Of the 57 patients, 50 (mean age, 64.2 years) were available after an average follow-up of 51 months. Clinical evaluation included the Constant Murley Score, the UCLA score, and the Simple Shoulder Test, whereas radiological evaluation included plain radiographs in standard projections. Patients were also requested to rate their subjective satisfaction of the final outcome as excellent, good, satisfied or dissatisfied.

Results

Compared to the preoperative status, the overall functional outcome measurements based on standardised outcome shoulder scores improved significantly at follow-up. The overall mean Constant Murley score improved from 18.5 to 49.3 points, the mean UCLA score improved from 7.1 to 21.6 points, and the mean simple shoulder test improved from 1.2 to 5.6 points. The average degree of abduction improved from 40 to 93° (p < 0.0001), and the average degree of anterior flexion improved from 47 to 98° (p < 0.0001). The median VAS pain score decreased from 7 to 1. Complications occurred in 12 cases (24 %).A total of 32 (64 %) patients rated their result as good or excellent, six (12 %) as satisfactory and 12 (24 %) as dissatisfied.

Conclusion

In revision shoulder arthroplasty after failed primary shoulder arthroplasty an inverse design can improve the functional outcome, and patient satisfaction is usually high. However, the complication rate of this procedure is also high, and patient selection and other treatment options should be carefully considered.