Diagnosing Sacroiliac Joint Pain.

The sacroiliac joint (SIJ) is a diarthrodial joint that has been implicated as a pain generator in approximately 10% to 25% of patients with mechanical low back or leg symptoms. Unique anatomic and physiologic characteristics of SIJ make it susceptible to mechanical stress and also create challenges in the diagnosis of SIJ pain. A variety of inciting causes for SIJ pain may exist, ranging from repetitive low-impact activities such as jogging to increased stress after multilevel spine fusion surgery to high-energy trauma such as in motor vehicle accidents. Similarly, wide variability exists in the clinical presentation of SIJ pain from localized pain or tenderness around the SIJ to radiating pain into the groin or even the entire lower extremity. No pathognomonic clinical history, physical examination finding, or imaging study exists that aids clinicians in making a reliable diagnosis. However, imaging combined with clinical provocative tests might help to identify patients for further investigation. Although provocative physical examination tests have not received reliable consensus, if three or more provocative tests are positive, pursuing a diagnostic SIJ injection is considered reasonable. Notable pain relief with intra-articular anesthetic injection under radiographic guidance has been shown to provide reliable evidence in the diagnosis of SIJ pain.

Natural History of Adolescent Idiopathic Scoliosis in Skeletally Mature Patients: A Critical Review.

The surgical treatment of adolescent idiopathic scoliosis is dependent on several factors, including curve type and magnitude, degree of curve progression, skeletal maturity, and other considerations, such as pain and cosmesis. The most common indication for surgery is curve progression. Most authors agree that surgical treatment should be considered in skeletally mature patients with curves > 50° because of the risk of progression into adulthood. Furthermore, most authors would agree that curves measuring < 40° to 45° in skeletally mature patients should be observed. When a skeletally mature patient with a curve measuring between 45° to 55° is presenting to an orthopaedic surgeon, it is not uncommon that the patient has no pain, no progression, and no imbalance. The generally accepted belief has been that curves that reach 50° are likely to progress into adulthood, progressing at a rate of 1° per year, based largely on the Iowa studies. However, the level of evidence for this is relatively weak, and the existing literature is equivocal in supporting the practice of performing surgery on these patients.

Accuracy and Reliability of Drawing Central Sacral Vertical Line on Scoliosis Radiographs in Clinical Practice.

STUDY DESIGN: Retrospective cross-sectional assessment of radiographs of adolescent idiopathic scoliosis. OBJECTIVE: To assess accuracy, reliability, and reproducibility of the central sacral vertical line (CVSL) on scoliosis radiographs and its influence on determining clinically relevant parameters: stable vertebra (SV) and lumbar modifier (LM). BACKGROUND SUMMARY: The central sacral vertical line is frequently used on scoliosis radiographs for surgical planning. However, no studies have assessed how accurately and reliably a physician draws CSVL in routine clinical practice. METHODS: We provided 30 digital posteroanterior X-rays of adolescent idiopathic scoliosis to 5 raters (3 fellowship-trained spine surgeons and 2 fellows) at 2 different times (3-week interval) to determine SV and LM. An independent observer then assessed the accuracy of CSVL drawn by the raters. The CSVL was considered accurate when it was drawn vertical from the middle of the S1 vertebra. To avoid conscious bias, we kept raters blinded as to the actual purpose of the study. To avoid technical bias, the study was conducted with research Picture Archiving and Communication Systems (PACS) software and raters used desktop computers similar to those in clinics or operating rooms. RESULTS: Based on absolute values, the CSVL was drawn on average 2.3 (±1.9) mm away from the center. Based on raw values, the lines were drawn on average 1.0 (±2.8) mm left of the center. We observed fair inter-rater reliability among the 5 raters, with an intra-class correlation of 0.23 (95% confidence interval, -0.33-0.59). Intra-rater reproducibility was moderate across 2 assessments, with an ICC of 0.47 (95% confidence interval, 0.27-0.62). Variation in drawing CSVL from center was not significantly associated with the selection of SV (r=-0.02; p=.78) or LM (r=-0.02; p=.78). CONCLUSION: Although, physicians draw CSVL significantly away from the center of the S1 vertebra (mean, 2.3 mm), its influence on determining SV or LM is not affected in routine practice.

Can preoperative radiographic parameters be used to predict fusion in non-instrumented posterolateral fusion for degenerative spondylolisthesis?

STUDY DESIGN: Prospective cohort. OBJECTIVE: To determine whether preoperative radiographic parameters (translation, angular motion, and lateral disc height) can predict fusion status in patients with degenerative spondylolisthesis who underwent a single-level decompression and non-instrumented posterolateral fusion using autogenous iliac crest bone graft. SUMMARY OF BACKGROUND DATA: Non-instrumented posterolateral fusion is sometimes considered in patients with degenerative spondylolisthesis who do not have radiographic evidence of instability. No previous study has attempted to determine whether preoperative radiographic parameters can be used to predict successful fusion. METHODS: A prospective, randomized, controlled, multicenter clinical study was previously conducted to compare the outcomes of osteogenic protein 1 (BMP-7) putty to autogenous iliac crest bone graft for single-level non-instrumented posterolateral fusion for the treatment of symptomatic degenerative spondylolisthesis with spinal stenosis. A total of 90 patients who were randomized to the autograft group formed the basis of this study, 67 of whom had data on the 3 radiographic parameters. Preoperative and postoperative radiographs were evaluated by 2 independent observers. The spine was determined to be fused if there was presence of continuous bone bridging between the transverse processes, an angulation of ≤5°, and a translational movement of ≤3 mm on flexion/extension radiographs of the affected level. RESULTS: Forty-two (63%) of the 67 patients had a radiographic fusion. The mean preoperative translation in this group was 1.87 mm (range, 0.3-7.35 mm), the angular motion was 4.44° (range, 0.1°-12.1°), and the lateral disc height was 8.74 mm (range, 0.2-15.34 mm). Twenty-five (37%) of the 67 patients had a radiographic pseudarthrosis. The mean preoperative translation in the pseudarthrosis group was 1.20 mm (range, 0-3.55 mm), the angular motion was 4.66° (range, 1.1°-12.95°), and the lateral disc space height was 8.10 mm (range, 1.98-13.315 mm). There was no significant difference in these 3 parameters between the fusion and the pseudarthrosis group. CONCLUSION: These results indicate that preoperative radiographic parameters that may indicate the absence of gross instability in degenerative spondylolisthesis are not reliable in predicting radiographic fusion in a single-level non-instrumented fusion.

Juvenile xanthogranuloma in an adult lumbar spine: a case report.

STUDY DESIGN: Case report. OBJECTIVE: To report a very rare case of juvenile xanthogranuloma (JXG) of the spine in an adult. SUMMARY OF BACKGROUND DATA: JXG is very rare in the spine, with only five prior reports in infants and children. To the best of our knowledge, this tumor has never been reported in an adult spine. METHODS: The patient is a 47-year-old woman who presented with bowel and bladder incontinence. Magnetic resonance imaging showed a very large lesion arising from the L2 vertebral body, with massive extension into the retroperitoneum with extensive intradural involvement. She had decreased rectal tone, had 4/5 strength in the right hip flexor, and had diminished sensation in her anterior right thigh and perineal region. She was otherwise neurologically intact. After preoperative embolization, a decompressive laminectomy was performed and the tumor was resected through a posterolateral transpedicular approach, followed by stabilization. Because of extensive involvement of retroperitoneum, complete resection was not possible. RESULTS: After pathologic evaluation of the specimen, a diagnosis of JXG was made. Patient underwent postoperative radiation therapy, and her neurologic examination improved significantly over the next several months. CONCLUSIONS: To the best of our knowledge, this is the first reported case of JXG in an adult spine. Although complete resection of the tumor was not possible, decompression of the dural sac followed by postoperative radiation led to an excellent clinical outcome.

Spinal orthoses.

External orthoses are used in the management of a variety of spinal disorders. Many types of brace are available to support the cervical, thoracic, and lumbar spine as well as junctional regions, which have special mechanical considerations. Many prefabricated and custom-made devices are available, made by a variety of manufacturers in this unregulated area of medical practice. Despite the widespread use of spinal orthoses, evidence of their efficacy in managing many spinal conditions is lacking. The most compelling indication for their use is in the management of traumatic spine injury. However, studies evaluating the efficacy of spinal orthoses have several shortcomings; many have evaluated orthoses that are no longer used. Recent data provide general guidelines to help the clinician choose the appropriate device.

Contemporary management of isthmic spondylolisthesis: pediatric and adult.

BACKGROUND: Isthmic spondylolisthesis is common in pediatric and adult patients. Most cases are asymptomatic. When symptomatic, nonsurgical treatment is an appropriate first step. Surgical treatment of this condition varies depending on patient age, degree of slip, presence of neurologic findings, and degree of deformity. PURPOSE: To review the literature on the management of isthmic spondylolisthesis in pediatric and adult patients. STUDY DESIGN: Review article. METHODS: Literature review. RESULTS AND CONCLUSIONS: Achieving a solid fusion leads to improved functional outcomes and reduction in pain. A circumferential fusion is associated with a higher fusion rate and has become more common, especially with high-grade slips. The need for reduction is controversial and is mostly indicated for patients with significant lumbosacral kyphosis and sagittal imbalance.

Distractive force relative to initial graft compression in an in vivo anterior cervical discectomy and fusion model.

STUDY DESIGN: An in vivo biomechanical anterior cervical discectomy and instrumented fusion (ACDFI) model employing a calibrated distractor and a subminiature load cell used to intraoperatively measure distractive force across the discectomy site and subsequent compressive force across the interbody load cell following distractor removal. OBJECTIVE: To determine the relationship between the distractive force and resultant initial graft compression in an in vivo ACDFI model. SUMMARY OF BACKGROUND DATA: The relationship between the distractive force and subsequent graft compression following distractor removal has not been studied in an in vivo ACDFI model. The consequences of over or under distraction and its subsequent effect on graft compression with regards to axial neck pain, endplate failure with graft subsidence, and fusion rates is an area of clinical significance for ACDFI. METHODS: Intraoperative measurements were obtained from 17 discectomy sites in 12 patients undergoing one and two level ACDFI. Informed consent was obtained from all subjects before surgery. A calibrated Caspar distractor was used to measure the distraction across the discectomy site and a subminiature interbody load cell was placed into the discectomy site and used to measure the resultant initial compressive force following distractor removal. The statistical significance and correlation between the distractive force across the discectomy site and the subsequent compressive force across the load cell were investigated with the Pearson correlation coefficient. RESULTS: The average distractive force across the discectomy site was 33.5 +/- 11.6 lbs and the subsequent compressive force across the interbody load cell was 16.9 +/- 5.9 lbs following distractor removal. The Pearson correlation coefficient was r = 0.912 (P < 0.0005). The data showed a statistically significant linear correlation between the distractive force and the subsequent compressive force across the range of distraction investigated. CONCLUSION: This study demonstrated a statistically significant linear correlation between the distractive force applied across the discectomy site and the subsequent compressive force across a load cell placed in the interbody space following distractor removal in an in vivo ACDFI model.

Bias in research.

Bias is a systematic inconsistency in research that contaminates the primary comparison. There are several forms of bias, and there are specific methods of minimizing them in different study designs. The randomized controlled trial (RCT) is the gold standard to which all other study designs are compared. However, errors can be made at various stages of a RCT that introduce bias. Furthermore, not all questions can be addressed by a RCT, and in some cases another study design may be more appropriate. Observational studies are more prone to bias, but, when properly conducted with rigorous methods to minimize bias, these studies can be valuable in clinical research.

Postlaminectomy kyphosis in an achondroplastic adolescent treated for spinal stenosis.

We report a case of a skeletally immature achondroplastic adolescent with significant thoracolumbar lordosis who presented with neurogenic claudication and urinary incontinence progressing over a 1-year period. She underwent decompressive lumbar laminectomy from T12 to L5 with preservation of the facet joints. Over the ensuing 4 years of follow-up, she developed a progressive thoracolumbar kyphosis that progressed to 105 degrees. She remained neurologically intact and was fully ambulatory, but had severe back pain in the area of the deformity. Because of the severity and progression of her deformity, a combined anterior and posterior fusion and stabilization was required. We present this case and a review of the literature on spinal stenosis in achondroplasia and the complication of post-laminectomy kyphosis.

Thumb abduction strength measurement in carpal tunnel syndrome.

PURPOSE: The strength of thumb abduction and index finger flexion was measured with a load cell mounted on a custom-made device. The resulting ratio (thumb-index ratio, or TIR) was used to diagnose carpal tunnel syndrome (CTS) and was compared with the gold standard (electrodiagnostic studies). The ratio was used as an internal control in each subject. METHODS: Sixty-one patients (80 hands) with a clinically and electrodiagnostically confirmed diagnosis of idiopathic CTS and a control group of 51 asymptomatic volunteers (102 hands) were evaluated. The strength of thumb abduction and index finger flexion was measured in standardized fashion in each hand three times, and the mean was taken to calculate TIR. RESULTS: Thumb-index ratio was statistically significant in differentiating between a CTS patient and a normal control. A TIR of 0.51 had a 98% specificity and a 92% positive predictive value for diagnosing CTS. Thumb-index ratio greater than 0.51 was neither sensitive nor specific for diagnosis of CTS. Twenty-four (30%) hands in the investigational group had a TIR < or =0.51 compared with 1 hand (1%) in the control group. There was a significant difference in the TIR between hands with a motor amplitude of < or =4.0 mV and those with an amplitude >4.0 mV. CONCLUSIONS: Most patients with CTS do not appear to have notable weakness of thumb abduction strength. A TIR < or =0.51 had high specificity for differentiating between CTS and controls. However, the performance of this device needs to be evaluated in a general population of patients who present with signs and symptoms of CTS before it would be clinically applicable.

Proximal row carpectomy.

BACKGROUND: Proximal row carpectomy is an accepted motion-sparing surgical procedure for the treatment of degenerative conditions of the wrist. However, there is little information regarding the long-term clinical and radiographic results following this procedure. METHODS: Twenty-two wrists in twenty-one patients underwent proximal row carpectomy for the treatment of degenerative arthritis between 1980 and 1992. Objective and subjective function was assessed after a minimum duration of follow-up of ten years (average, fourteen years). RESULTS: There were four failures (18%) requiring fusion at an average of seven years. All four failures occurred in patients who were thirty-five years of age or less at the time of the proximal row carpectomy (p = 0.03). The wrists that did not fail had an average flexion-extension arc of 72 degrees , associated with an average grip strength of 91% of that on the contralateral side. The patients were very satisfied with fourteen of the eighteen wrists that did not fail and were satisfied with the remaining four. The patients rated nine wrists as not painful, four as mildly painful, five as moderately painful, and none as severely painful. The average Disabilities of the Arm, Shoulder and Hand score was 9 points. Radiographs revealed no loss of the radiocapitate space in three of the seventeen wrists for which radiographs were made, reduced space in seven, and complete loss of the space in seven. With the numbers available, there was no significant association between loss of joint space seen on radiographs and subjective and objective function. CONCLUSIONS: At the time of long-term followup, all patients older than thirty-five years of age at the time of a proximal row carpectomy had maintained a satisfactory range of motion, grip strength, and pain relief and were satisfied with the result. Caution should be exercised in performing the procedure in patients younger than thirty-five years of age. Although degeneration of the radiocapitate joint was seen radiographically in fourteen of the seventeen wrists, it did not preclude a successful clinical result.