Surgical outcome after treatment of thoracolumbar spinal stenosis in adults with achondroplasia.

PURPOSE: To describe the complications and the outcome of patients with achondroplasia undergoing thoracolumbar spinal surgery. METHODS: Retrospective analysis of prospectively collected data of all patients with achondroplasia undergoing surgery within the years 1992-2021 at the thoracic and/or lumbar spine. The outcome was measured by analyzing the surgical complications and revisions. The patient-rated outcome was assessed with the COMI score from 2005 onwards. RESULTS: A total of 15 patients were included in this study undergoing a total of 31 surgeries at 79 thoracolumbar levels. 12/31 surgeries had intraoperative complications consisting of 11 dural tears and one excessive intraoperative bleeding. 4/18 revision surgeries were conducted due to post-decompression hyperkyphosis. The COMI score decreased from 7.5 IQR 1.4 (range 7.1-9.8) preoperatively to 5.3 IQR 4.1 (2.5-7.5) after 2 years (p = 0.046). CONCLUSION: Patients with achondroplasia, the most common skeletal dysplasia condition with short-limb dwarfism, are burdened with a congenitally narrow spinal canal and are commonly in need of spinal surgery. However, surgery in these patients is often associated with complications, namely dural tears and post-decompression kyphosis. Despite these complications, patients benefit from surgical treatment at a follow-up of 2 years after surgery.

Computer-assisted correction of incongruent distal radioulnar joints in patients with symptomatic ulnar-minus variance.

Our study described a computer-assisted, three-dimensional (3-D), planned surgical technique of a radial shortening osteotomy. The osteotomy of the distal radius was planned with computer assistance on 3-D bone models based on computed tomography data. The objective was to maximize the contact zone of the sigmoid notch with the ulnar head. Between 2012 and 2020 we treated 14 wrists in 11 patients with symptomatic ulnar-minus variance with a mean follow-up of 44 months (range 8 to 98) and a mean age of 28 years (range 19 to 38). Postoperatively, patients showed a decrease in pain at rest and during effort (numeric rating scale from 4.4 to 0 and 7.5 to 4.5, respectively). The range of motion postoperatively was similar to the contralateral side. Grip strength increased from 24 kg to 30 kg. The Disability of the Arm, Shoulder, and Hand and the Patient-Rated Wrist Evaluation scores were 28 and 35 postoperatively, respectively. Our technique of 3-D computer-assisted distal radioulnar joint reconstruction led to a pain reduction and improvement of the hand function in patients with symptomatic ulnar-minus variance.Level of evidence: IV.

The Metatarsal Cortical Index as an Indicator of Insufficiency Fracture of the Foot.

The diagnosis of metatarsal stress fractures is challenging. Standard imaging often shows false-negative results. The aim of this study was to create reliable radiologic outcome parameters to predict insufficiency fractures of the metatarsals. We performed an age- and sex-matched case-control study of patients with (n = 18) and without insufficiency fracture (n = 18) of the foot. The metatarsal cortical index (MCI) for each metatarsal was developed to predict an insufficiency fracture. The MCI of each metatarsal was significantly decreased in the insufficiency fracture group compared with the control group (p < .01). The MCI of the fourth ray yielded the highest area under the curve among the analyzed MCI values (area under the curve, 0.79; 95% confidence interval, 0.61-0.90). A cut-off value of 1.62 for the MCI of the fourth ray yielded a sensitivity of 78% and a specificity of 78% to predict insufficiency fracture of the foot (odds ratio, 12.25; 95% confidence interval, 2.54-58.97), and enabled accurate allocation to the insufficiency fracture group versus the control group in 74% of cases. In conclusion, a decreased MCI is associated with metatarsal insufficiency fractures and enables an accurate diagnosis in 3 out of 4 cases. The MCI might aid clinicians in identifying insufficiency fracture, and raise the suspicion of the diagnosis without additional imaging studies.

Musculoskeletal biomechanics of patients with or without adjacent segment degeneration after spinal fusion.

STUDY DESIGN: A retrospective, single center, case-control study was performed. OBJECTIVE: The present study employed patient-specific biomechanical modeling to find potential biomechanical differences after spinal fusion at L4/5 in patients with and without subsequent development of adjacent segment disease (ASD). METHODS: The study population comprised patients who underwent primary spinal fusion at L4/5 and were either asymptomatic during > 4 years of follow-up (CTRL; n = 18) or underwent revision surgery for ASD at L3/4 (n = 20). Landmarks were annotated on preoperative and follow-up lateral radiographs, and specific musculoskeletal models were created using a custom-built modeling pipeline. Simulated spinal muscle activation and lumbar intervertebral shear loads in unfused segments were analyzed in upright standing and forward flexion. Differences between the pre- and postoperative conditions were computed for each patient. RESULTS: The average postoperative muscle activity in the upright standing posture was 88.4% of the preoperative activity in the CTRL group (p <  0.0001), but did not significantly change from pre- to postoperatively in the ASD group (98.0%). The average shear load magnitude at the epifusional joint L3/4 during upright standing increased from pre- to postoperatively in the ASD group (+ 3.9 N, +/- 17.4 (n = 18)), but decreased in the CTRL group (- 4.6 N, +/- 23.3 (n = 20); p <  0.001). CONCLUSION: Patient-specific biomechanical simulation revealed that spinal fusion surgery resulted in greater shear load magnitude and muscle activation and therefore greater forces at the epifusional segment in those with ASD compared with those without ASD. This is a first report of patient-specific disc load and muscle force calculation with predictive merits for ASD.

How Should We Grade Cervical Disk Degeneration? A Comparison of Two Popular Classification Systems.

INTRODUCTION: Despite being originally developed for the evaluation of lumbar disk degeneration, the Pfirrmann classification has emerged as the most popular classification system for cervical disk degeneration. However, with the Suzuki classification, a new classification system that is specifically tailored for the evaluation of cervical disk disease was introduced. In this study, we aim to evaluate differences in inter- and intraobserver reliability of both classifications in a head-to-head comparison. METHODS: In total, we have evaluated 120 cervical disks within 40 patients via magnetic resonance imaging according to the Pfirrmann and Suzuki classification. The degree of disk degeneration was evaluated by two independent musculoskeletal radiologists. After 6 months, the classification was reassessed to evaluate the intraobserver reliability. The inter- and intraobserver reliabilities were then calculated using Cohen's kappa. RESULTS: The inter- and intraobserver reliability provided a significant agreement between all ratings in Pfirrmann as well as the Suzuki classification (p>0.001). The interobserver reliability was determined to be fair in both the Suzuki classification (κ=0.290) and the Pfirrmann classification (κ=0.265). The intraobserver reliability was substantial in the Suzuki classification (κ=0.798), while it was almost perfect in the Pfirrmann classification (κ=0.858). CONCLUSIONS: Although not designed for the evaluation of cervical disk degeneration, the Pfirrmann classification yielded equal inter- and higher intraobserver reliability. Both classification systems are viable options for the grading of cervical disk degeneration. While the Pfirrmann classification has the advantage of being better established, the Suzuki classification may be clinically superior due to a better representation of cervical disk degeneration and the consideration of disk bulging for the classification of cervical disk degeneration.

Non-Adherence to Pain Medication Increases Risk of Postoperative Frozen Shoulder.

BACKGROUND: Postoperative frozen shoulder (FS) or adhesive capsulitis is a relatively frequent complication (5-20%), even after simple arthroscopic shoulder surgeries. The pathophysiology is still unclear, but psychological factors may play a pivotal role. From clinical experience, we hypothesized that patients, who are reluctant to take medications, particularly "pain-killers," have an increased incidence of postoperative FS. METHODS: We identified twenty patients who underwent limited arthroscopic operations of the shoulder and developed postoperative FS. Twenty patients with matching type of surgery, age, and gender served as control group (n = 20). All patients were at least one year postoperative and asymptomatic at the time of examination. Demographic data, the patient's adherence to self-medication (including self-medicating scale, SMS), development the Quality of life (QoL), and depression scale (PHQ-4-questionnaire) were assessed. RESULTS: Patients with FS had a 2-fold longer rehabilitation and 3-fold longer work inability compared to the patients without FS (P < 0.009 and P < 0.003, respectively). Subjective shoulder value SSV (P = 0.075) and post-operative improvement of QoL (P = 0.292) did not differ among the groups. There was a trend-but not significant-toward less coherence to self-medication in the FS-group (26.50 vs. 29.50; P = 0.094). Patients with postoperative FS significantly more often stated not to have "taken pain-killers as prescribed" (P = 0.003). CONCLUSIONS: Patients reporting unwillingness to take the prescribed pain medications had a significantly higher incidence of postoperative FS. It remains unclear whether the increased risk of developing FS is due to reduced postoperative analgesia or a critical attitude toward taking medication. However, patients who are reluctant to take painkillers should strongly be encouraged to take medications as prescribed.

Sternoclavicular joint injections and their predictive value for the outcome of surgery.

BACKGROUND: Sternoclavicular joint injections are one of the first-line treatment options for painful non-infectious pathologies of the sternoclavicular joint; however, their long-term effects and predictive value in decision-making for surgery are yet to be defined. METHODS: 27/32 Patients who received in total 36 computed tomography-guided sternoclavicular joint injections in 2012-2017 replied the questionnaire with a mean follow-up of 38 months after the first sternoclavicular joint injection. Of those patients, seven underwent subsequent surgery. We evaluated pain response after sternoclavicular joint injection and American Shoulder and Elbow Surgeons-score at later follow-up. RESULTS: Directly after sternoclavicular joint injection, pain decreased from Visual Analog Scale 5.3 ± 2.4 to 3.8 ± 3 (p = 0.001). In the seven patients who underwent surgery for degenerative changes, definitive outcome correlated with pain relief after the last infiltration (r = 0.86, p = 0.012). Also, the final American Shoulder and Elbow Surgeons-score was lower in patients with multiple injections compared to those who were satisfied after the first injection (p = 0.019). DISCUSSION: Sternoclavicular injections are a useful tool in the context of degenerative sternoclavicular joint disorders as the amount of pain reduction is, in case the short-term effect is not long-lasting, at least a strong indicator for the future success of operative treatment.

Posttraumatic Carpal Instability Nondissociative.

Background Posttraumatic midcarpal instability nondissociative (CIND) is an exceptional rare condition, therefore the outcome after different treatment options remains unknown. Questions The purpose of this study was to investigate the different treatment options for posttraumatic CIND. We also describe the different radiological and magnetic resonance imaging (MRI) findings in this patient cohort. Patients and Methods We present outcomes of 10 patients who developed CIND following acute wrist trauma between 2007 and 2018, 3 with dorsal intercalated segment instability pattern (CIND-DISI) and 7 with volar intercalated segment instability (CIND-VISI) radiographically. Results Three patients with CIND-VISI had satisfactory outcomes with conservative treatment. Two patients with irreducible CIND-DISI and one with CIND-VISI underwent proximal row carpectomy (PRC), two with reducible CIND-VISI had radiolunate fusion, and two with secondary osteoarthritis had total wrist fusion. All patients with CIND-DISI needed surgery, whereas only four of the seven patients with CIND-VISI needed surgery. On MRI, all three patients with CIND-DISI had rupture of the radiolunate ligament. Conclusions The data collected in this study may provide the first step toward better understanding of the pathology for this exceptionally rare finding. In CIND-VISI, we have not seen any ligament injury in four patients. Therefore, conservative therapy is more likely to be the first step. In CIND-DISI, we recommend an operative procedure: if detected early, with ligament suture, otherwise by radiolunate fusion, PRC, or total wrist fusion. Level of Evidence This is a Level IV study.

Epiphyseal lymphoid infiltrates of the knee in adolescents.

We present three adolescents with focal lesions of the distal femur that were shown to be benign aggregates of small lymphocytes and plasma cells of unknown origin. The patients were within the age of 12 and 14 years. All lesions presented with similar MRI findings and provided the same histopathological findings in the biopsy. Although all lesions increased in size, only one patient remained symptomatic and underwent subsequent tumor resection. To our best knowledge, tumor or pseudotumoral epiphyseal lymphoid infiltrates as seen in these three patients have not previously been described. We recommend a biopsy to rule out a malignant tumor or an infection. Observation, without further invasive testing in asymptomatic patients, is recommended until the resolution of the lesions. However, if a lesion becomes symptomatic, surgical resection should be considered.

Cervical disc degeneration reduces distance between vertebral artery and surgical landmarks.

PURPOSE: Anterior cervical decompression surgery exposes the vertebral artery to the risk of injury. This risk can increase if the natural course of the vertebral artery is altered. Therefore, this study evaluated if the distance between surgical landmarks and the vertebral artery decrease with the progression of cervical disc degeneration. METHODS: This study analyzed 40 patients with cervical magnetic resonance imaging. We evaluated the distance between the uncinate process and the vertebral artery in axial-plane T2 weighted sequences of the cervical levels C3-C6. The cervical disc degeneration was graded according to the Pfirrmann- and Suzuki classification. The decrease of the distance was evaluated using a one-way ANOVA. RESULTS: The distance between the uncinate process and the vertebral artery decreased with increasing disc degeneration (p ≤ 0.015). ROC analysis provided an acceptable area under the curve in both classifications for the detection of a vertebral artery to the uncinate process distance of zero. The presence of Pfirrmann grade V had a positive predictive value of 69% for the presence of contact between the uncinate process and the vertebral artery. CONCLUSION: High-grade cervical disc degeneration according to the Pfirrmann- and the Suzuki classification decrease the distance between the uncinate process and the vertebral artery. High-grade disc degeneration therefore should raise the awareness of the surgeon for the loss of the distance between surgical landmarks and the vertebral artery. However, screening for high-grade disc degeneration alone cannot substitute the thorough evaluation of the anatomical course of the vertebral artery before surgery.

Cartilage and extensor tendon defects after headless compression screw fixation of phalangeal and metacarpal fractures.

Osteosynthesis of metacarpal and phalangeal fractures with headless compression screws leads to a defect in the articular surface and possibly damage to the extensor tendons. This study aimed to quantify the articular surface defect and extensor tendon injuries after implant placement in cadaveric hands. Defect size was assessed with computed tomography. Extensor tendon injuries were assessed by direct visualization and measurement after dissection. In the middle phalanx, the defect size in relation to the joint surface was significantly smaller after anterograde screw placement when compared with retrograde placement. Also, a mini-open approach was found to cause significantly less tendon injury than a percutaneous approach, but there was no difference in tendon damage between retrograde and antegrade screw insertion into the middle phalanx.

How many screws are necessary for subtalar fusion? A retrospective study.

BACKGROUND: Biomechanical studies have shown a higher compressive force and higher torsional stiffness for fixation with three screws compared to two screws. However, clinical data to compare these fixation techniques is still lacking. METHODS: A retrospective analysis of 113 patients was performed, who underwent isolated subtalar fusion between January 2006 and April 2018. RESULTS: Revision arthrodesis was required in 8% (n=6/36) for 3-screw-fixation and 38% (n=35/77) for 2-screw-fixation. For 3-screw-fixation, non-union, was observed in 14% (n=5/36) compared to 35% (n=27/77) in 2-screw fixation. Non-union (p=.025) and revision arthrodesis (p=.034) were significantly more frequent in patients with 2 screws. A body mass index ≥30kg/m2 (p=.04, OR=2.6,95%CI:1.1-6.3), prior ankle-fusion (p=.017,OR=4.4,95%CI:1.3-14.5) and diabetes mellitus (p=.04,OR=4.9,95%CI:1.1-17.8) were associated with a higher rate of revision arthrodesis. CONCLUSIONS: Our findings suggest that successful subtalar fusion is more reliably achieved with use of three screws. However, future prospective studies will be necessary to further specify this recommendation.