Clinical primary flexor tendon repair and rehabilitation: The Bern Experience

In this chapter we present our experience with treatment of zone 2 flexor tendon repair using a six-strand repair technique combined with postoperative place-and-hold exercise. The six-strand Lim/Tsai repair technique combined with place-and-hold exercises demonstrated better digital function compared to a two-strand repair without place-and-hold exercises. Range of motion in the Lim/Tsai repair group appeared to be increased without a higher rate of ruptures but with a shorter rehabilitation period. The fact that the two groups differed in both suture techniques and rehabilitation programs made it impossible to know whether the better results in the group of Lim/Tsai were due to the six-strand repair or the place-and-hold exercises or both. Despite the obvious benefit of early active mobilization, an active motion protocol may not always be possible to apply in a substantial number of patients due to concomitant injuries, the quality of the surgical repair or patient factors (swelling, pain, limited compliance). Since August 2006 a staged rehabilitation program (“stop and go”) was introduced within our unit using early active controlled flexion (green), place-and-hold (yellow), or passive flexion exercises (red) introduced by Kleinert-Duran. Our experience using the six-strand suture repair technique and “stop and go” is outlined.

Radialer externer Fixateur zur geschlossenen Behandlung problematischer suprakondylärer Humerusfrakturen Typ III und IV bei Kindern und Jugendlichen

Operationsziel Geschlossene, anatomische Reposition und sichere Fixation von problematischen suprakondylären Typ-III- und Typ-IV-Humerusfrakturen, die mit den herkömmlichen Operationsmethoden nur schwierig geschlossen zu behandeln sind. Indikationen Gemäß der AO-Kinderklassifikation der suprakondylären Humerusfrakturen vom Typ III und IV: Frakturen, welche nicht geschlossen mittels üblicher Repositionsmethoden reponierbar sind sowie Frakturen, die nicht mittels der üblichen, gekreuzten perkutanen Kirschner-Draht-Technik zu fixieren sind. Bei schweren Schwellungszuständen, offener Fraktur oder initial neurologischen und/oder vaskulären Problemen („pulseless pink hand“) sowie bei mehrfachverletzten Kindern, welche eine optimale Rehabilitation benötigen und die Extremität gipsfrei sein sollte. Bei Kindern mit Komorbiditäten (z. B. Anfälle, Spastizität), die eine bessere Stabilität benötigen. Kontraindikationen Prinzipiell keine Kontraindikationen Operationstechnik Im nichtreponierten Zustand unter Durchleuchtungskontrolle Einbringen einer einzelnen Schanz-Schraube in den lateralen (radialen) Aspekt des distalen Fragments, welches sich in der streng seitlichen Röntgenprojektion als „Sand-Uhr“- bzw. Kreisform des Capitulum humeri darstellt. Je nach Größe dieses distalen Fragments kann die Schanz-Schraube rein epiphysär oder metaphysär liegen. Danach in absolut streng seitlicher Projektion des distalen Humerus im Bereich des meta-diaphysären Übergangs Einbohren einer 2. Schanz-Schraube unabhängig von der Ersten, die möglichst rechtwinklig zur Längsachse des Humerus in der a.-p.-Ebene zu liegen kommen sollte, um spätere Manipulationen mittels „Joy-Stick“-Technik zu erleichtern. Sind die beiden Schanz-Schrauben mehr oder weniger in beiden Ebenen parallel, so ist die Fraktur praktisch anatomisch reponiert. Nach erreichter Reposition Feinjustierung aller Achskomponenten. Sicherung der Flexion/Extension mittels einem von radial, distal eingebrachten sog. Anti-Rotations-Kirschner-Drahts, der die Stabilität signifikant erhöht und eine Drehung des distalen Fragments um die einzelne Schanz-Schraube verhindert. Postoperative Behandlung Keine zusätzliche Gipsruhigstellung notwendig. Es sollte eine funktionelle Nachbehandlung erfolgen. Ergebnisse Gemäß unserer Langzeitstudien bewegen die meisten Kinder bereits zum Zeitpunkt der ambulanten Pin-Entfernung in der Frakturambulanz ihren Ellbogen weitgehend normal. Bei einer Follow-up-Zeit über 40 Monate hatten 30/31 Kindern eine seitengleiche Achse und Beweglichkeit.

Is the acetabular cup orientation after total hip arthroplasty on a two dimension or three dimension model accurate?

Purpose Malposition of the acetabular component in total hip arthroplasty (THA) is a common surgical problem that can lead to hip dislocation, reduced range of motion and may result in early loosening. The aim of this study is to validate the accuracy and reproducibility of a single x-ray image based 2D/3D reconstruction technique in determining cup inclination and anteversion against two different computer tomography (CT)-based measurement techniques. Methods Cup anteversion and inclination of 20 patients after cementless primary THA was measured on standard anteroposterior (AP) radiographs with the help of the single x-ray 2D/3D reconstruction program and compared with two different 3D CT-based analyses [Ground Truth (GT) and MeVis (MV) reconstruction model]. Results The measurements from the single x-ray 2D/3D reconstruction technique were strongly correlated with both types of CT image-processing protocols for both cup inclination [R²=0.69 (GT); R²=0.59 (MV)] and anteversion [R²=0.89 (GT); R²=0.80 (MV)]. Conclusions The single x-ray image based 2D/3D reconstruction technique is a feasible method to assess cup position on postoperative x-rays. CTscans remain the golden standard for a more complex biomechanical evaluation when a lower tolerance limit (+/-2 degrees) is required.

Relative femoral neck lengthening improves pain and hip function in proximal femoral deformities with a high-riding trochanter

BACKGROUND Complex proximal femoral deformities, including an elevated greater trochanter, short femoral neck, and aspherical head-neck junction, often result in pain and impaired hip function resulting from intra-/extraarticular impingement. Relative femoral neck lengthening may address these deformities, but mid-term results of this approach have not been widely reported. QUESTIONS/PURPOSES Do patients who have undergone relative femoral neck lengthening show (1) less hip pain and greater function; (2) improved radiographic parameters; (3) significant complications requiring subsequent surgery; and (4) progression of osteoarthrosis (OA) or conversion to total hip arthroplasty (THA) at mid-term followup? METHODS We retrospectively reviewed 40 patients (41 hips) with isolated relative femoral neck lengthening between 1998 and 2006 with sequelae of Legg-Calvé-Perthes disease (38 hips [93%]), slipped capital femoral epiphysis (two hips [5%]), and postseptic arthritis (one hip [2%]). During this time, the general indications for this procedure included a high-riding greater trochanter with a short femoral neck with abductor weakness and symptomatic intra-/extraarticular impingement. Mean patient followup was 8 years (range, 5-13 years), and complete followup was available in 38 patients (39 hips [95%]). We evaluated pain and function with the impingement test, limp, abductor force, Merle d'Aubigné-Postel score, and range of motion. Radiographic parameters included trochanteric height, alpha angle, and progression of OA. Subsequent surgeries, complications, and conversion to THA were summarized. RESULTS The proportion of positive anterior impingement tests decreased from 93% (38 of 41 hips) preoperatively to 49% (17 of 35 hips) at latest followup (p = 0.002); the proportion of limp decreased from 76% (31 of 41 hips) to 9% (three of 35 hips; p < 0.001); the proportion of normal abductor strength increased from 17% (seven of 41 hips) to 91% (32 of 35 hips; p < 0.001); mean Merle d'Aubigné-Postel score increased from 14 ± 1.7 (range, 9-17) to 17 ± 1.5 (range, 13-18; p < 0.001); mean internal rotation increased to 25° ± 15° (range, 0°-60°; p = 0.045), external rotation to 32° ± 14° (range, 5°-70°; p = 0.013), and abduction to 37° ± 13° (range, 10°-50°; p = 0.004). Eighty percent of hips (33 of 41 hips) showed normal trochanteric height; alpha angle improved to 42° ± 10° (range, 27°-90°). Two hips (5%) had subsequent surgeries as a result of lack of containment; four of 41 hips (10%) had complications resulting in reoperation. Fourteen of 35 hips (40%) showed progression of OA; four of 40 hips (10%) converted to THA. CONCLUSIONS Relative femoral neck lengthening in hips with combined intra- and extraarticular impingement results in reduced pain, improved function, and improved radiographic parameters of the proximal femur. Although lack of long-term complications is gratifying, progression of OA was not prevented and remains an area for future research.

Surgical Technique: Reverse Periacetabular Osteotomy

Acetabular retroversion is the result of an externally rotated hemipelvis rather than a focal overgrowth of the anterior wall and/or hypoplasia of the posterior wall. Acetabular retroversion is a cause of pincer impingement which, if left untreated, can lead to hip pain and osteoarthritis. The causal surgical treatment in hips with acetabular retroversion is acetabular reorientation with a reverse periacetabular osteotomy (PAO). Indication is based on a positive correlation among symptoms (typically groin pain), physical findings on examination (positive anterior impingement test and decreased flexion and internal rotation), and radiographic signs for acetabular retroversion. These include a positive crossover, posterior wall, and ischial spine sign. A reverse PAO is performed with four osteotomies and a controlled fracture. Unlike reorientation of the acetabular fragment in dysplastic hips, correction for acetabular retroversion is achieved by a combined extension and internal rotation of the acetabular fragment. Typically, a small supra-acetabular wedge resection is required to allow sufficient extension of the fragment. The quality of acetabular reorientation is evaluated by intraoperative AP pelvic radiographs. In addition, intraoperative testing of range of motion following acetabular reorientation is mandatory. An arthrotomy and offset correction of the femoral head-neck area is indicated in hips with decreased internal rotation following acetabular reorientation. In a 10-year follow-up study of reverse PAO, a favorable outcome with preservation of all native joints was found. Correct acetabular orientation and, if necessary, a concomitant offset correction were the keys of successful outcome.

Long-term Outcome After Monosegmental L4/5 Stabilization for Degenerative Spondylolisthesis With the Dynesys Device.

STUDY DESIGN Retrospective analysis of prospectively collected clinical data. OBJECTIVE To assess the long-term outcome of patients with monosegmental L4/5 degenerative spondylolisthesis treated with the dynamic Dynesys device. SUMMARY OF BACKGROUND DATA The Dynesys system has been used as a semirigid, lumbar dorsal pedicular stabilization device since 1994. Good short-term results have been reported, but little is known about the long-term outcome after treatment for degenerative spondylolisthesis at the L4/5 level. METHODS A total of 39 consecutive patients with symptomatic degenerative lumbar spondylolisthesis at the L4/5 level were treated with bilateral decompression and Dynesys instrumentation. At a mean follow-up of 7.2 years (range, 5.0-11.2 y), they underwent clinical and radiographic evaluation and quality of life assessment. RESULTS At final follow-up, back pain improved in 89% and leg pain improved in 86% of patients compared with preoperative status. Eighty-three percent of patients reported global subjective improvement. Ninety-two percent would undergo the surgery again. Eight patients (21%) required further surgery because of symptomatic adjacent segment disease (6 cases), late-onset infection (1 case), and screw breakage (1 case). In 9 cases, radiologic progression of spondylolisthesis at the operated segment was found. Seventy-four percent of operated segments showed limited flexion-extension range of <4 degrees. Adjacent segment pathology, although without clinical correlation, was diagnosed at the L5/S1 (17.9%) and L3/4 (28.2%) segments. In 4 cases, asymptomatic screw loosening was observed. CONCLUSIONS Monosegmental Dynesys instrumentation of degenerative spondylolisthesis at L4/5 shows good long-term results. The rate of secondary surgeries is comparable to other dorsal instrumentation devices. Residual range of motion in the stabilized segment is reduced, and the rate of radiologic and symptomatic adjacent segment degeneration is low. Patient satisfaction is high. Dynesys stabilization of symptomatic L4/5 degenerative spondylolisthesis is a possible alternative to other stabilization devices.

Population doublings and percentage of S100-positive cells as predictors of in vitro chondrogenicity of expanded human articular chondrocytes

The aim of this study was to investigate the interconnection between the processes of proliferation, dedifferentiation, and intrinsic redifferentiation (chondrogenic) capacities of human articular chondrocyte (HAC), and to identify markers linking HAC dedifferentiation status with their chondrogenic potential. Cumulative population doublings (PD) of HAC expanded in monolayer culture were determined, and a threshold range of 3.57-4.19 PD was identified as indicative of HAC loss of intrinsic chondrogenic capacity in pellets incubated without added chondrogenic factors. While several specific gene and surface markers defined early HAC dedifferentiation process, no clear correlation with the loss of intrinsic chondrogenic potential could be established. CD90 expression during HAC monolayer culture revealed two subpopulations, with sorted CD90-negative cells showing lower proliferative capacity and higher chondrogenic potential compared to CD90-positive cells. Although these data further validated PD as critical for in vitro chondrogenesis, due to the early shift in expression, CD90 could not be considered for predicting chondrogenic potential of HAC expanded for several weeks. In contrast, an excellent mathematically modeled correlation was established between PD and the decline of HAC expressing the intracellular marker S100, providing a direct link between the number of cell divisions and dedifferentiation/loss of intrinsic chondrogenic capacity. Based on the dynamics of S100-positive HAC during expansion, we propose asymmetric cell division as a potential mechanism of HAC dedifferentiation, and S100 as a marker to assess chondrogenicity of HAC during expansion, of potential value for cell-based cartilage repair treatments.

Combining 3D tracking and surgical instrumentation to determine the stiffness of spinal motion segments: a validation study

The spine is a complex structure that provides motion in three directions: flexion and extension, lateral bending and axial rotation. So far, the investigation of the mechanical and kinematic behavior of the basic unit of the spine, a motion segment, is predominantly a domain of in vitro experiments on spinal loading simulators. Most existing approaches to measure spinal stiffness intraoperatively in an in vivo environment use a distractor. However, these concepts usually assume a planar loading and motion. The objective of our study was to develop and validate an apparatus, that allows to perform intraoperative in vivo measurements to determine both the applied force and the resulting motion in three dimensional space. The proposed setup combines force measurement with an instrumented distractor and motion tracking with an optoelectronic system. As the orientation of the applied force and the three dimensional motion is known, not only force-displacement, but also moment-angle relations could be determined. The validation was performed using three cadaveric lumbar ovine spines. The lateral bending stiffness of two motion segments per specimen was determined with the proposed concept and compared with the stiffness acquired on a spinal loading simulator which was considered to be gold standard. The mean values of the stiffness computed with the proposed concept were within a range of ±15% compared to data obtained with the spinal loading simulator under applied loads of less than 5 Nm.

Treatment of the symptomatic healed Perthes hip

Healed Legg-Calvé-Perthes disease may cause both intra-articular and extra-articular impingement, resulting in a symptomatic hip prior to the onset of osteoarthritis. Various impingement-relieving surgeries have been used in the past; however, the development of the safe surgical dislocation technique has allowed a better understanding of complex deformity that may be present in these hips and hence may improve treatment of these symptomatic prearthritic hips. This article outlines the range of deformities possible in a Perthes hip, and treatment strategies to surgically address these deformities. For Perthes disease good preoperative clinical and radiographic assessment is essential, and intraoperative assessment vital.

Quantitative mapping of T2 using partial spoiling

Fast quantitative MRI has become an important tool for biochemical characterization of tissue beyond conventional T1, T2, and T2*-weighted imaging. As a result, steady-state free precession (SSFP) techniques have attracted increased interest, and several methods have been developed for rapid quantification of relaxation times using steady-state free precession. In this work, a new and fast approach for T2 mapping is introduced based on partial RF spoiling of nonbalanced steady-state free precession. The new T2 mapping technique is evaluated and optimized from simulations, and in vivo results are presented for human brain at 1.5 T and for human articular cartilage at 3.0 T. The range of T2 for gray and white matter was from 60 msec (for the corpus callosum) to 100 msec (for cortical gray matter). For cartilage, spatial variation in T2 was observed between deep (34 msec) and superficial (48 msec) layers, as well as between tibial (33 msec), femoral, (54 msec) and patellar (43 msec) cartilage. Excellent correspondence between T2 values derived from partially spoiled SSFP scans and the ones found with a reference multicontrast spin-echo technique is observed, corroborating the accuracy of the new method for proper T2 mapping. Finally, the feasibility of a fast high-resolution quantitative partially spoiled SSFP T2 scan is demonstrated at 7.0 T for human patellar cartilage.

Glycoprotein D of bovine herpesvirus 5 (BoHV-5) confers an extended host range to BoHV-1 but does not contribute to invasion of the brain

Bovine herpesvirus 1 (BoHV-1) and BoHV-5 are closely related pathogens of cattle, but only BoHV-5 is considered a neuropathogen. We engineered intertypic gD exchange mutants with BoHV-1 and BoHV-5 backbones in order to address their in vitro and in vivo host ranges, with particular interest in invasion of the brain. The new viruses replicated in cell culture with similar dynamics and to titers comparable to those of their wild-type parents. However, gD of BoHV-5 (gD5) was able to interact with a surprisingly broad range of nectins. In vivo, gD5 provided a virulent phenotype to BoHV-1 in AR129 mice, featuring a high incidence of neurological symptoms and early onset of disease. However, only virus with the BoHV-5 backbone, independent of the gD type, was detected in the brain by immunohistology. Thus, gD of BoHV-5 confers an extended cellular host range to BoHV-1 and may be considered a virulence factor but does not contribute to the invasion of the brain.

Influence of preoperative functional status on outcome after total hip arthroplasty

BACKGROUND: International registries with large, heterogeneous patient populations provide excellent research opportunities for studying factors that influence treatment outcomes after total hip arthroplasty. In the present study, we used a European multinational database to investigate whether there is an association between three functional variables (preoperative pain, mobility, and motion) and functional outcome. METHODS: We performed a retrospective cohort study on preoperative and follow-up clinical data that were prospectively entered into the International Documentation and Evaluation System European hip registry between 1967 and 2002. The inclusion criteria for this study were an age of more than twenty years, an underlying diagnosis of osteoarthritis, and a Charnley class-A functional designation at the time of surgery. A total of 12,925 patients (13,766 total hip arthroplasties) who met these criteria were entered into the analysis. Three functional variables (pain, mobility, and motion) that were assessed preoperatively were evaluated postoperatively at various follow-up examinations for a maximum of ten years. RESULTS: Six thousand four hundred and one patients could walk longer than ten minutes preoperatively; of these, 57.1% had a walking capacity of more than sixty minutes at the time of the most recent follow-up. In comparison, 6896 patients had a preoperative walking capacity of less than ten minutes and only 38.9% of these patients could walk more than sixty minutes at the time of the most recent follow-up. The difference was significant (p < 0.01). Similarly, 10,375 patients had a preoperative hip flexion range of >70 degrees ; of these, 74.7% had a flexion range of >90 degrees at the time of the most recent follow-up. In comparison, 2793 patients had a preoperative hip flexion range of <70 degrees and only 62.6% of these patients had a flexion range of >90 degrees at the time of the most recent follow-up. The difference was also significant (p < 0.01). Lasting, complete, or almost complete pain relief was achieved by >80% of the patients following total hip arthroplasty regardless of their preoperative categorization of pain. CONCLUSIONS: Patients with poor preoperative walking capacity and hip flexion are less likely to achieve an optimal outcome with regard to walking and motion. In contrast, there is no correlation between the preoperative pain level and pain alleviation, which is generally good and long-lasting after total hip arthroplasty.

Application and assessment of a robust elastic motion correction algorithm to dynamic MRI

The purpose of this study was to assess the performance of a new motion correction algorithm. Twenty-five dynamic MR mammography (MRM) data sets and 25 contrast-enhanced three-dimensional peripheral MR angiographic (MRA) data sets which were affected by patient motion of varying severeness were selected retrospectively from routine examinations. Anonymized data were registered by a new experimental elastic motion correction algorithm. The algorithm works by computing a similarity measure for the two volumes that takes into account expected signal changes due to the presence of a contrast agent while penalizing other signal changes caused by patient motion. A conjugate gradient method is used to find the best possible set of motion parameters that maximizes the similarity measures across the entire volume. Images before and after correction were visually evaluated and scored by experienced radiologists with respect to reduction of motion, improvement of image quality, disappearance of existing lesions or creation of artifactual lesions. It was found that the correction improves image quality (76% for MRM and 96% for MRA) and diagnosability (60% for MRM and 96% for MRA).

Radiological anatomy of the obturator nerve and its articular branches: basis to develop a method of radiofrequency denervation for hip joint pain

OBJECTIVE: A previous study of radiofrequency neurotomy of the articular branches of the obturator nerve for hip joint pain produced modest results. Based on an anatomical and radiological study, we sought to define a potentially more effective radiofrequency method. DESIGN: Ten cadavers were studied, four of them bilaterally. The obturator nerve and its articular branches were marked by wires. Their radiological relationship to the bone structures on fluoroscopy was imaged and analyzed. A magnetic resonance imaging (MRI) study was undertaken on 20 patients to determine the structures that would be encountered by the radiofrequency electrode during different possible percutaneous approaches. RESULTS: The articular branches of the obturator nerve vary in location over a wide area. The previously described method of denervating the hip joint did not take this variation into account. Moreover, it approached the nerves perpendicularly. Because optimal coagulation requires electrodes to lie parallel to the nerves, a perpendicular approach probably produced only a minimal lesion. In addition, MRI demonstrated that a perpendicular approach is likely to puncture femoral vessels. Vessel puncture can be avoided if an oblique pass is used. Such an approach minimizes the angle between the target nerves and the electrode, and increases the likelihood of the nerve being captured by the lesion made. Multiple lesions need to be made in order to accommodate the variability in location of the articular nerves. CONCLUSIONS: The method that we described has the potential to produce complete and reliable nerve coagulation. Moreover, it minimizes the risk of penetrating the great vessels. The efficacy of this approach should be tested in clinical trials.

Altered perception of apparent motion in schizophrenia spectrum disorder

Apparent motion (AM), the Gestalt perception of motion in the absence of physical motion, was used to study perceptual organization and neurocognitive binding in schizophrenia. Associations between AM perception and psychopathology as well as meaningful subgroups were sought. Circular and stroboscopic AM stimuli were presented to 68 schizophrenia spectrum patients and healthy participants. Psychopathology was measured using the Positive and Negative Syndrome Scale (PANSS). Psychopathology was related to AM perception differentially: Positive and disorganization symptoms were linked to reduced gestalt stability; negative symptoms, excitement and depression had opposite regression weights. Dimensions of psychopathology thus have opposing effects on gestalt perception. It was generally found that AM perception was closely associated with psychopathology. No difference existed between patients and controls, but two latent classes were found. Class A members who had low levels of AM stability made up the majority of inpatients and control subjects; such participants were generally young and male, with short reaction times. Class B typically contained outpatients and some control subjects; participants in class B were older and showed longer reaction times. Hence AM perceptual dysfunctions are not specific for schizophrenia, yet AM may be a promising stage marker.