Posterolateral Quadrant Research Articles

Does index tumor predominant location influence prognostic factors in radical prostatectomies?

ABSTRACTPurpose To find any influence on prognostic factors of index tumor according to predominant location.Materials and Methods Prostate surgical specimens from 499 patients submitted to radical retropubic prostatectomy were step-sectioned. Each transverse section was subdivided into 2 anterolateral and 2 posterolateral quadrants. Tumor extent was evaluated by a semi-quantitative point-count method. The index tumor (dominant nodule) was recorded as the maximal number of positive points of the most extensive tumor area from the quadrants and the predominant location was considered anterior (anterolateral quadrants), posterior (posterolateral quadrants), basal (quadrants in upper half of the prostate), apical (quadrants in lower half of the prostate), left (left quadrants) or right (right quadrants). Time to biochemical recurrence was analyzed by Kaplan-Meier product-limit analysis and prediction of shorter time to biochemical recurrence using univariate and multivariate Cox proportional hazards model.Results Index tumors with predominant posterior location were significantly associated with higher total tumor extent, needle and radical prostatectomy Gleason score, positive lymph nodes and preoperative prostate-specific antigen. Index tumors with predominant basal location were significantly associated with higher preoperative prostate-specific antigen, pathological stage higher than pT2, extra-prostatic extension, and seminal vesicle invasion. Index tumors with predominant basal location were significantly associated with time to biochemical recurrence in Kaplan-Meier estimates and significantly predicted shorter time to biochemical recurrence on univariate analysis but not on multivariate analysis.Conclusions The study suggests that index tumor predominant location is associated with prognosis in radical prostatectomies, however, in multivariate analysis do not offer advantage over other well-established prognostic factors.

The anterolateral supra-fibular-head approach for plating posterolateral tibial plateau fractures: A novel surgical technique

ObjectiveThe posterolateral (PL) tibial plateau quadrant is laterally covered by the fibular head and posteriorly covered by a mass of muscle ligament and important neurovascular structures. There are several limitations in exposing and fixing the PL tibial plateau fractures using a posterior approach. The aim of this study is to present a novel anterolateral supra-fibular-head approach for plating PL tibial plateau fractures. MethodsFive fresh and ten preserved knee specimens were dissected to measure the following parameters:1) the vertical distance from the apex of the fibular head to the lateral plateau surface, 2) the transverse distance between the PL platform and fibula collateral ligament (FCL), and 3) the tension of the FCL in different knee flexion positions. Clinically, isolated PL quadrant tibial plateau fractures were treated via an anterolateral supra-fibular-head approach and lateral rafting plate fixation. The outcome of the patients was assessed after a short to medium follow-up period. ResultsThe distance from the apex of the fibular head to the lateral condylar surface was 12.2±1.6mm on average. With the knee extended and the FCL tensioned, the transverse distance between the PL platform and the FCL was 6.7±1.1mm. With the knee flexed to 60° and the FCL was in the most relaxed position, the distance increased to 21.1±3.0mm. Clinically, a series of 7 cases of PL tibial plateau fractures were treated via this anterolateral supra-fibular-head approach. The patient was placed in a lateral decubitus position with the knee flexed to approximately 60 degrees. After the posterior retraction of the FCL, the plate was placed more posteriorly to provide a raft or horizontal belt fixation of the PL tibial plateau fragment. After an average of 14.3 months of follow up, the knee range of motion(ROM) was 121.4°±8.8° (range: 105°-135°), the HSS score was 96.7±2.6 (range: 90-100), and the SMFA dysfunction score was 22.4±3.8 (range: 16-28) points. ConclusionThe anterolateral supra-fibular-head approach can provide direct visualization of the posterolateral tibial plateau quadrant and put the plate more posteriorly to provide a raft for the fragments such that good clinical outcomes can be anticipated.

Combined lateral femoral epicondylar osteotomy and a submeniscal approach for the treatment of a tibial plateau fracture involving the posterolateral quadrant

Exposure of a tibial plateau fracture involving the posterolateral quadrant is challenging, and several approaches for treating these fractures have been introduced. However, these approaches may have limited applicability, and they can potentially cause neurovascular, musculotendinous, or ligamentous injury of the posterolateral corner. Lateral femoral epicondylar osteotomy has been used for meniscal transplantation, total knee arthroplasty, and the treatment of posterolateral articular disorders of the femur and tibia. We encountered a case of a tibial plateau fracture involving the posterolateral quadrant without an anterior-extending fracture line. We successfully exposed, reduced, and fixed the fracture using combined lateral femoral epicondylar osteotomy and a submeniscal approach. This combined modality can be used as an alternative surgical technique for the treatment of tibial plateau fractures involving the posterolateral quadrant.

Schatzker type IV medial tibial plateau fractures: a computed tomography-based morphological subclassification.

Schatzker type IV medial tibial plateau fractures have an unfavorable prognosis, likely due to the mechanism of injury (fracture-dislocation/subluxation type) and possibly due to the involvement of the posterolateral plateau, which is different from previously thought. The aim of this study was to propose a new subclassification of Schatzker type IV fracture patterns based on 2-dimensional (2-D) computed tomography and three-dimensional (3-D) reconstruction. The authors defined Schatzker type IV medial tibial plateau fractures as AO/OTA 41 type B fractures (partial articular), with partial or total medial plateau involvement, leaving at least the anterolateral quadrant intact. The images of 42 fractures (42 patients) were evaluated. The fractures were further anatomically divided into 2 groups: Group 1 were classic medial unicondylar fractures and Group 2 were more complicated variants involving both condyles, characterized by medial condyle fractures with lateral plateau extension, usually with articular impaction of the centroposterior lateral plateau. Twelve (29%) cases involved only the medial condyle, and 30 (71%) involved both the medial and lateral condyles. Twenty-nine (69%) cases demonstrated posterior coronal fractures. The most common patterns were bicondylar posteromedial plateau fractures with posterolateral quadrant depression (bicondylar posterior fractures: 14 cases, 33%) and total/subtotal medial condyle fractures with posterolateral quadrant depression (13 cases, 31%). The isolated unicondylar posteromedial split fracture was uncommon (2 cases, 5%). Computed tomography-based reconstruction enhances the understanding of fracture anatomy and the relationships between fracture fragments. In Schatzker type IV medial tibial plateau fractures, the involvement of posterolateral quadrants is common.

Posterolateral fragment characteristics in tibial plateau fractures

Dear Editor, We read the article “Morphological characteristics of split-depression fractures of the lateral tibial plateau (Schatzker type II): a computer-tomography-based study” by Zhai et al. [1] with great interest. To the best of our knowledge, this report presents the largest number of case series concerning posterolateral tibial plateau fractures. Posterolateral quadrant tibial plateau fractures are a hot topic in recent years in orthopaedic traumatology. This unique fracture pattern is relatively common in China because of the wide use of electric bicycles in daily life [2]. This kind of bicycle is a lower speed (<20 km/h) personal vehicle driven by storage battery. When riding an electric bicycle, the person is sitting with his/her knees relaxed in a 90° position. When the bicycle falls onto one side, an axial compression load with valgus force is applied to the posterior tibial plateau with the knee in flexed position, which is prone to result in posterolateral quadrant fracture of the lateral plateau. This is the reason why most clinical reports on this fracture pattern come from China [1–4]. Posterolateral quadrant fracture can occur in isolation (only involving the posterolateral quadrant) or in combination (involving more than one quadrant). Several factors, such as the force direction, magnitude, and contact location, as well as the position of the knee at impact, may determine the fracture pattern, location, and degree of displacement. A thorough understanding of fracture morphology can help surgeons better understand the mechanism of injury and select an appropriate treatment plan. In recent years some authors [1–5], most from mainland China, investigated the fracture features and found the fracture patterns in posterolateral quadrants are usually depression or split-depression, the fragments are usually in conical shape with a relatively small articular surface area, short cortical split length and limited articular depression depth (Table 1). Isolated posterolateral quadrant fractures are usually low-energy trauma, while combined posterolateral fractures are high-energy trauma. The concomitant fibular head fracture is also an indicator of high-energy trauma and is significantly associated with greater displacement of the posterolateral fracture fragments. Table 1 Posterolateral fragment characteristics in tibial plateau fractures With the large number of cases, in our opinion, Dr. Zhai et al. [1] can provide more detailed data in subgroups, for example, stratified by differentiation of fracture area involving only the posterolateral one quadrant (isolated pattern) from posterolateral and anterolateral two quadrants (combined patterns), and by fracture patterns with or without concomitant fibular head fractures. As such, the posterolateral fragment morphology may be more specific and useful for treatment strategy selections, such as operative or nonoperative, and different surgical approaches and fragment fixation modes. Yours faithfully, Qing Li, MD Ying-Qi Zhang, MD Shi-Min Chang, MD, PhD

Bloqueo axilar ecoguiado: variaciones anatómicas de la disposición de los 4 nervios terminales del plexo braquial en relación con la arteria humeral

ObjectivesTo describe the distribution of the terminal branches of the brachial plexus at the axillary level and define distribution patterns after ultrasound evaluation. Material and methodFifty volunteers underwent ultrasound bilateral axillary brachial plexus scanning exploration. Nerve distribution around the humeral artery was described and the distance between each nerve and the center of the artery was measured. The distance and relationship between the ulnar nerve and the humeral vein were also recorded. ResultsThe median nerve was located in the anterolateral quadrant (−29±40°) and at a mean distance of 2.1±0.9mm from the artery (85%). The ulnar nerve was found at 53±26° and at 4.2±2.1mm from the artery in the anteromedial quadrant (90%), anterolateral to the vein in 46% of cases, and deep to it in 54%. The radial nerve was at 122±38° and at 3.3±1.7mm from the artery in the posteromedial quadrant (86%). The musculocutaneous nerve was found at −103±22° and 9.3±5.6mm from the artery in the posterolateral quadrant (90%) and in the anterolateral quadrant (−55±16°) at 4.8±2.7mm (10%). There were no differences regarding laterality, gender or overweight patients. ConclusionsOur results allow defining four different anatomical patterns, two based in the position of the musculocutaneous nerve and two based on the disposition of the ulnar nerve with respect to the humeral vein. These patterns were not related to laterality, gender or body weight.

Prostate Total Tumor Extent Versus Index Tumor Extent—Which is Predictive of Biochemical Recurrence Following Radical Prostatectomy?

It is controversial whether tumor extent in radical prostatectomies predicts biochemical recurrence following surgery. We compared the predictive value of total tumor extent vs dominant nodule (index tumor) extent. A mean of 32 paraffin blocks was processed from prostate surgical specimens step sectioned at 3 to 5 mm intervals from 300 patients treated with radical retropubic prostatectomy. Each transverse section was subdivided into 2 anterolateral and 2 posterolateral quadrants. Tumor extent was evaluated by a semiquantitative point count method. Dominant nodule extent was recorded as the maximal number of positive points of the largest single focus of cancer in the quadrants. Time to biochemical recurrence was analyzed by Kaplan-Meier product limit analysis. Prediction of shorter time to biochemical recurrence was determined by univariate and multivariate Cox proportional hazards models. Except for age and race, total and index tumor extent was significantly associated with higher preoperative prostate specific antigen, clinical stage T2, pathological stage greater than T2, positive surgical margins and higher radical prostatectomy Gleason score. Total and index tumor extent was significantly associated with time to biochemical recurrence in Kaplan-Meier estimates. Total and index tumor extent significantly predicted shorter time to biochemical recurrence on univariate analysis but only index tumor extent was an independent predictor of time to biochemical recurrence on multivariate analysis. The study indicates that any tumor extent estimate in surgical specimens should be related to the dominant nodule (index tumor) and not to total tumor extent.

Regional variations in radial head bone volume and density: implications for fracture patterns and fixation

Fractures of the radial head are common with most partial articular fractures resulting in an anterolateral fragment. The exact mechanism of radial head fracture is unknown; however, forces transmitted and variations in local bone density are believed important. This study quantifies the regional variations in bone density and volume of the radial head to better understand the pathomechanics of fracture patterns. Computer tomography scan data of 18 cadaver elbows were imported into imaging analysis software. The radial head was divided into quadrants based on neutral forearm rotation. Bone density and volume were calculated and compared between quadrants. The regional densities of bone expressed in Hounsfield units (HU) were posteromedial quadrant (PM) 496 ± 87 HU, anteromedial quadrant (AM) 443 ± 72 HU, anterolateral quadrant (AL) 409 ± 60 HU, and posterolateral quadrant (PL) 406 ± 57 HU. The volume of bone in descending order was PM 1138 ± 179 mm(3), PL 1013 ± 213 mm(3), AM 1010 ± 210 mm(3), and AL 938 ± 175 mm(3). The PM quadrant was significantly denser than the AM, AL, and PL quadrants, (P = .001) and the AM quadrant was significantly denser than the AL and PL quadrants (P = .006 and .009). The PM quadrant had significantly more bone volume when compared to the AM, AL, and PL (P = .001). The AM and PL quadrants had significantly greater bone volume compared to AL quadrant (P = .023 and .018, respectively). Radial head bone volume and density is highest in the posteromedial quadrant and lowest in the anterolateral quadrant where fractures occur more frequently.

A comparative study of the trabecular bony architecture of the talus in humans, non-human primates, and Australopithecus

This study tested the hypothesis that talar trabecular microarchitecture reflects the loading patterns in the primate ankle joint, to determine whether talar trabecular morphology might be useful for inferring locomotor behavior in fossil hominins. Trabecular microarchitecture was quantified in the anteromedial, anterolateral, posteromedial, and posterolateral quadrants of the talar body in humans and non-human primates using micro-computed tomography. Trabecular bone parameters, including bone volume fraction, trabecular number and thickness, and degree of anisotropy differed between primates, but not in a manner entirely consistent with hypotheses derived from locomotor kinematics. Humans have highly organized trabecular struts across the entirety of the talus, consistent with the compressive loads incurred during bipedal walking. Chimpanzees possess a high bone volume fraction, consisting of plate-like trabecular struts. Orangutan tali are filled with a high number of thin, connected trabeculae, particularly in the anterior portion of the talus. Gorillas and baboons have strikingly similar internal architecture of the talus. Intraspecific analyses revealed no regional differences in trabecular architecture unique to bipedal humans. Of the 22 statistically significant regional differences in the human talus, all can also be found in other primates. Trabecular thickness, number, spacing, and connectivity density had the same regional relationship in the talus of humans, chimpanzees, gorillas, and baboons, suggesting a deeply conserved architecture in the primate talus. Australopithecus tali are human-like in most respects, differing most notably in having more oriented struts in the posteromedial quadrant of the body compared with the posterolateral quadrant. Though this result could mean that australopiths loaded their ankles in a unique manner during bipedal gait, the regional variation in degree of anisotropy was similar in humans, chimpanzees, and gorillas. These results collectively suggest that the microarchitecture of the talus does not simply reflect the loading environment, limiting its utility in reconstructing locomotion in fossil primates.

Ein modifizierter posterolateraler Zugang für die operative Versorgung von Tibiakopffrakturen

Open reduction and internal fixation of posterolateral tibial plateau fractures. Tibial plateau fractures involving the posterolateral quadrant. Critical soft-tissue conditions. Tibial plateau fractures which do not involve the posterolateral quadrant. 90 degrees side positioning on the contralateral side, skin incision along the fibular head, exposure of the peroneal nerve, lateral arthrotomy and exposure of the joint, dissection of the popliteal cavity between the lateral head of the gastrocnemius muscle and soleus muscle. Blunt preparation between popliteus muscle and soleus muscle under preservation of the popliteal artery and vein. Sharp dissection of the soleus muscle from the dorsal parts of fibula and tibia until the peroneal nerve at the fibular neck enters into the muscle. Exposure of the posterolateral tibial head. The dorsal joint capsule and the popliteal corner are prevented from any soft-tissue damage. Visual control of fracture reduction by viewing in the joint gap through lateral arthrotomy. Reduction of the fracture from dorsal with pointed reduction forceps. A conventional or locking radius T-plate can be pinched off with lateral cutters and anatomically bent for fracture fixation and is dorsally fixed at the tibial plateau. 10 kg partial weight bearing for 6-8 weeks. Limited range of motion 0-0-90 degrees for 6 weeks. In a period of 2 years, seven patients with posterolateral tibial plateau fractures received open reduction and internal fixation by using the modified posterolateral approach. The patients were examined at follow-up between 12 and 24 months after surgery. Six patients were free of pain with full range of motion and stable knee joints. Radiologically, a good fracture reduction was achieved in six cases. In one patient with a posterolateral comminuted dislocation fracture, a small fracture step and a gap could be observed. No approach-related complications were found.

The Dipolar ElectroCARdioTOpographic (DECARTO)–like method for graphic presentation of location and extent of area at risk estimated from ST-segment deviations in patients with acute myocardial infarction

A graphic method was developed for presentation of the location and extent of the myocardium at risk in patients with acute myocardial infarction (AMI). This method is based on a mathematical processing of ST-segment deviations of standard 12-lead electrocardiogram following the concept of Titomir and Ruttkay-Nedecky in their dipolar electrocardiotopographic method. The center of the location of the area at risk is given by the spatial orientation of the resultant spatial ST vector, and the extent of the area at risk is derived from the Aldrich score. The areas at risk are projected on a spherical image surface, on which a texture of the anatomical quadrants of the ventricular surface and its coronary artery supply are projected. The method was tested in 10 patients with AMI with single-vessel disease, including 6 patients with an occlusion in the proximal left anterior descending coronary artery (LAD), 3 patients with an occlusion in the right coronary artery, and one patient with occlusion in the left circumflex coronary artery. The estimated areas at risk were compared with myocardial perfusion single photon emission computed tomography. Eight (80%) patients of 10 were correctly localized according to the Aldrich decision rules for the location of AMI. The areas at risk in patients with LAD occlusion correctly localized by the Aldrich score were situated in the anteroseptal and anterosuperior quadrants. In the inferior AMI group, the area at risk was localized in the posterolateral and inferior quadrants. The visual comparison with myocardial perfusion single photon emission computed tomography (SPECT) showed best agreement in patients with LAD involvement. The initial testing showed that this method allows a graphic presentation of estimated area at risk using clinically defined diagnostic rules. The area at risk can be displayed in images that are familiar for clinicians and can be compared with or superimposed on results of other imaging methods used in cardiology.

Evaluation of Bernese periacetabular osteotomy

Evaluation of Bernese periacetabular osteotomy

Iatrogenic and non-iatrogenic positive margins: incidence, site, factors involved, and time to PSA progression following radical prostatectomy

There are conflicting data regarding the incidence, site and prognostic significance of positive margins resulting from iatrogenic incision into the prostate (pT2+) or non-iatrogenic inability to excise extraprostatic extension (EPE) of tumor. The surgical specimens were whole-mount processed. Nerve-sparing, tumor extension and Gleason score were considered possible factors involved in positive margins. Time to PSA progression was studied using a Kaplan-Meier product-limit analysis. Positive margins resulted from iatrogenic incision in 61/230 (26.52%) prostates and from EPE in 34/230 (14.78%) prostates. The site most frequently involved in pT2+ prostates was the posterolateral quadrants (40.98%); in cases with EPE both anterolateral and posterolateral quadrants (67.65%) were most frequently involved. Positive margins occurred equally in patients with and without nerve-sparing in both groups. Tumors were significantly more extensive and with higher Gleason score in patients with EPE. Time to PSA progression was similar in patients with pT2+ versus EPE and no invasion of the seminal vesicle, but was significantly shorter in patients with EPE and invasion of the seminal vesicle. The frequency of positive margins in our institution was similar to others with large experience in performing radical prostatectomies. The higher frequency of posterolateral quadrants in iatrogenic positive margins is probably related to the preservation of adjacent vital structures and not to nerve-sparing surgery. A trend for a decreasing frequency of non-iatrogenic surgical margins may be explained by the marked increase of clinical stage T1c in recent years. More-extensive tumors and higher Gleason scores seem to influence only non-iatrogenic positive margins. Biochemical (PSA) progression in EPE must be studied by stratifying the patients into two groups: with and without seminal vesicle invasion.

Goldenhar-Associated Conditions (hemifacial microsomia) and Congenital Deformities of the Spine

We performed a retrospective study of 668 consecutive patients with congenital spine deformities. To determine the prevalence of Goldenhar conditions in patients with congenital spine deformities, and describe the types of vertebral abnormalities and their treatment. The craniofacial malformations described by Goldenhar can be associated with congenital vertebral anomalies. This nonrandom association represents unilateral errors in the morphogenesis of the spine, the first and second branchial arches. The medical records were reviewed, and patients with Goldenhar conditions were identified. The vertebral anomalies causing spine deformity were detected on radiographs. The type and site of the craniofacial abnormalities, other musculoskeletal deformities, and systemic anomalies were recorded. There were 14 patients, including 7 males and 7 females, who had Goldenhar conditions. Thoracic scoliosis was the most common deformity, occurring in 10 patients (71.5%). Of these patients, 8 had an isolated hemivertebra, and the remaining 2 had a unilateral unsegmented bar with contralateral hemivertebra at the same level. There was only 1 patient with lumbar scoliosis caused by a hemivertebra. The side of vertebral anomaly correlated with that of hemifacial microsomia in 5 of 11 patients with scoliosis or kyphoscoliosis. Thoracolumbar kyphosis occurred in 4 patients, including 2 who had posterior hemivertebrae, 1 who had wedge vertebrae, and the remaining who had an anterior unsegmented bar. Thoracolumbar kyphoscoliosis occurred in only 1 patient because of a posterolateral quadrant vertebra. Klippel-Feil syndrome occurred in 6 patients (42.8%). There were 8 patients (57%) who underwent surgical treatment at a mean age of 9.8 years (range 2.9-19). Four patients had undergone a combined anterior-posterior, and 4 had a posterior-only spine arthrodesis. The prevalence of Goldenhar-associated conditions in patients with congenital spine deformities was 2%. Failures of vertebral segmentation were the most frequent abnormality in the cervical spine, whereas failures of vertebral formation most commonly occurred in the thoracic or thoracolumbar spine.

Prospective bone density changes after periacetabular osteotomy: a methodological study

We used computed tomography (CT) and 3D design-based sampling principles (stereology) to estimate changes in acetabular bone density after periacetabular osteotomy. We included six consecutive patients with hip dysplasia in the study. Baseline density was measured within the first 7 days following periacetabular osteotomy and compared with bone density 2 years later. Double measurements were performed on three patients, and the coefficient of error of the mean was estimated to 0.05. Bone density in zone 1 increased significantly in the anteromedial quadrant as well as in the posteromedial quadrant of the acetabulum. In the anterolateral and the posterolateral quadrant, bone density was unchanged. In zone 2 and 3, bone density was unchanged 2 years postoperatively. We suggest that the observed increase in bone density medially represents a remodelling response to an altered load distribution after osteotomy. The method used is a precise tool to estimate changes in acetabular bone density.

Mechanical properties of subchondral cancellous bone of the radial head.

To quantify the mechanical properties of subchondral bone of the radial head, with special interest in the regional variations in bone stiffness and strength. Transverse subchondral cancellous bone slices obtained from the proximal radial head were subjected to indentation tests. Biomechanics laboratory with a servohydraulic materials testing machine. Thirteen previously frozen, cadaver proximal radii of mean age 69 +/- 9 years. The mean indentation modulus and local yield strength were calculated for the anteromedial (AM), anterolateral (AL), posteromedial (PM), and posterolateral (PL) quadrants of the radial head. There were no differences in mean indentation modulus across all 4 quadrants (AL, 55.56 +/- 16.20 MPa; AM, 53.48 +/- 20.67 MPa; PM, 49.20 +/- 18.31 MPa; PL, 49.96 +/- 14.97 MPa) (P > 0.05). The AM quadrant had higher local yield strength than the PL and PM quadrants, as did the AL compared with the PL quadrant (AL, 24.89 +/- 8.52 Mpa; AM, 28.39 +/- 10.52 Mpa; PM, 23.01 +/- 6.99; PL, 20.62 +/- 4.83 MPa) (P < 0.05). This suggests that the high frequency of radial head fractures in the AL quadrant is likely not due to the local strength of cancellous bone. Rather, the location of fracture may be influenced by the composite strength or the mechanisms of loading at the radiocapitellar and proximal radioulnar joints. The modulus results suggest that similar screw purchase can be achieved in all areas of the radial head during internal fixation of fractures. These results may also influence implant design and fixation. This study was limited to an older population and may not be representative of a younger population.

Natural history of congenital kyphosis and kyphoscoliosis. A study of one hundred and twelve patients.

Congenital kyphosis and kyphoscoliosis are much less common than congenital scoliosis. However, they are potentially more serious because compression of the spinal cord and paraplegia sometimes develop. The goals of the present study were to document the natural history of congenital kyphosis and kyphoscoliosis and to determine the stage at which the natural progression should be interrupted by treatment. We reviewed the medical records and radiographs of the spine of 112 consecutive patients. Sixty-eight patients had a type-I kyphosis due to an anterior failure of vertebral-body formation, twenty-four had a type-II kyphosis due to an anterior failure of vertebral-body segmentation, and twelve had a type-III kyphosis due to a combination of anomalies; the deformities of the remaining eight patients could not be classified. Eighty-five skeletally immature, untreated patients were first evaluated at a mean age of six years and nine months (range, two months to sixteen years and three months), and twenty-seven patients were skeletally mature at the time of the first visit. Sixty-three of the eighty-five skeletally immature patients were observed without any treatment for a mean period of six years and six months (range, one to sixteen years) before skeletal maturity, and the remaining twenty-two patients had a posterior arthrodesis of the spine soon after the initial visit. At skeletal maturity, forty-one patients had not been treated and sixty-eight had had an arthrodesis of the spine. The remaining three patients had not yet reached skeletal maturity at the time of the most recent follow-up. The apex of the kyphosis was seen at all levels but was most frequent between the tenth thoracic and the first lumbar level (seventy-four patients; 66 percent). There was no relationship between the severity of the kyphosis and its location in the spine. Progression of the curve was most rapid during the adolescent growth spurt and stopped only at skeletal maturity. Progression was most rapid and the magnitude of the curve was the greatest in type-III kyphosis (twelve patients) followed by type-I kyphosis due to a posterolateral quadrant vertebra (thirty-nine patients), a posterior hemivertebra (eight patients), a butterfly vertebra (fifteen patients), and a wedged vertebra (six patients). A kyphosis due to two adjacent type-I vertebral anomalies progressed more rapidly and produced a more severe deformity than did a similar single anomaly. The prognosis for type-II kyphosis was variable and was much more severe when an anterolateral unsegmented bar had produced a kyphoscoliosis (nine patients) than it was when a midline anterior bar had produced a pure kyphosis (fifteen patients), which usually progressed slowly. Spontaneous neurological deterioration due to compression of the spinal cord occurred in ten patients (seven of whom had a type-I kyphosis and three of whom had an unclassifiable anomaly) at a mean age of thirteen years and eight months, and one other patient (with an unclassifiable anomaly) had spastic paraparesis at the age of twenty-eight years. Congenital kyphosis and kyphoscoliosis are uncommon deformities with the potential to progress rapidly, resulting in severe deformity and possible neurological deficits. A thorough knowledge of the natural history is essential in the planning of appropriate and timely treatment to prevent progression of the deformity and neurological complications.

Acetabular coverage of the femoral head after triple pelvic osteotomy: no relation to outcome in 51 hips followed for 8-15 years.

In developmental dysplasia of the hip in adolescents and young adults, pelvic osteotomies aim to improve acetabular coverage of the femoral head by reorienting the acetabulum. We determined whether acetabular coverage is related to long-term clinical results after triple osteotomy of the pelvis. We used a previously published computer program (Konishi and Mieno 1993) which calculates three-dimensional coverage of the femoral head from plain anteroposterior radiographs. We studied the pelvic radiographs of 51 hips in 43 patients and the results were correlated with studies on clinical outcome (de Kleuver et al. 1997). Total acetabular coverage improved from a mean of 56% to 70%. We did not find a relationship between total acetabular coverage and long-term outcome, nor could we determine an optimal coverage. Reduced coverage of the posterolateral quadrant of the femoral head was related to a reduced score for walking ability (p = 0.03), and therefore care should be taken not to overcorrect the acetabulum forwards when attempting to improve the deficient anterior coverage. We challenge the concept that total acetabular coverage is a prerequisite for a good long-term outcome after triple pelvic osteotomy, and hypothesize that other factors such as the change in load across the hip are probably more important in determining the outcome.

The effect of fibular malreduction on contact pressures in an ankle fracture malunion model.

Nine fresh-frozen cadaveric specimens were disarticulated through the knee, and the soft tissues, except for the interosseous ligaments and interosseous membrane, were removed to the level of the ankle. The subtalar joint was secured with screws in neutral position (approximately 5 degrees of valgus). Contact pressures in the tibiotalar joint were measured with use of low-grade pressure-sensitive film, which was placed through an anterior capsulotomy. For each measurement, 700 newtons of load was applied to the specimen for one minute. The film imprints were scanned, and the contact pressures were quantitated in nine equal quadrants over the talar dome. A fracture-displacement device was secured to the distal end of the fibula; the device allowed for individual or combined displacements consisting of shortening, lateral shift, and external rotation of the fibula. The ankle was maintained in neutral flexion. The ligamentous injury associated with a pronation-lateral rotation fracture of the ankle was simulated by dividing the deep fibers of the deltoid ligament, the anterior-inferior tibiofibular ligament, and the interosseous membrane to a point that was an average of fifty-three millimeters proximal to the ankle joint. Baseline contact area and contact pressure in the joint were determined, followed by measurements after two, four, and six millimeters of shortening of the fibula; after two, four, and six millimeters of lateral shift of the fibula; and after 5, 10, and 15 degrees of external rotation of the fibula. The three types of displacement were tested individually as well as in combination. The simulated deformities were found to cause a shift of the contact pressure to the mid-lateral and posterolateral quadrants of the talar dome, with pressures as high as 4.1 megapascals. A corresponding decrease in the contact pressures was noted in the medial quadrants of the talar dome. The highest pressures were recorded for maximum shortening of the fibula, the combination of maximum shortening and lateral shift, the combination of maximum shortening and external rotation, and the combination of maximum shortening, lateral shift, and external rotation. In general, increases in each displacement variable corresponded to increasing contact pressures.

Posterolateral arthritis of the knee

Arthritis in the posterolateral quadrant of the knee presents typical arthroscopic findings. With careful history, physical examination, and appropriate radiographs, it can be an office diagnosis. The history, physical findings, and arthroscopic findings in 15 patients with this problem were reviewed. Symptoms of posterolateral pain, give-way, and pain with stairclimbing were common. The only frequent physical findings were those of pain with the lateral meniscal entrapment test or pain with the pivot shift test. No ligamentous instability was noted. Weight-bearing radiographs demonstrated severe lateral chondral loss in flexion, but not in extension. Arthroscopic findings were typical. Previous injury to the posterior portion of the lateral meniscus was common. This seems to be a traumatic rather than a degenerative, process. Three patients had varus-producing osteotomy of the distal femur. This was not effective in relieving their symptoms.