Knee Capsule Research Articles

A RANDOMIZED CONTROLLED TRIAL TO EVALUATE THE ANTI-INFLAMMATORY EFFECT OF COMMIPHORA WIGHTII IN COMBINATION WITH CURCUMA LONGA AGAINST DICLOFENAC POTASSIUM IN NON-SPECIFIC KNEE EFFUSION

Knee effusion is an abnormal accumulation of the fluid in the knee capsule or the adjoining supra - patellar bursa secondary to the irritation/inflammation in the joint synovium. It is seen in approximately 8 - 10 % of the to tal patients suffering from osteo - arthrosis. Kro ṣṭ ukaśīr ṣ a as described in Ayurveda , can be corelated with knee effusion. In Present clinical trial an effort has been made to evaluate anti - inflammatory effect of Commiphora wightii in combination with Curcum a longa against Diclofenac potassium [NSAID’s] in Non - specific knee effusio n. Total tw enty two , clinically diagnosed patients of Non - specific knee effusion were selected for the present clinical trial excluding drop out 2 0 patients were assorted in to t wo groups Trial Group and control Groups. Trial Group 10 pa tients were given crude extract of Commiphora wightii 500 mg along with Curcuma longa 500 mg in a separate capsule twice a day continuously for 8 weeks orally . In Control Group ten patients were given Diclofenac Potassium 50 mg twice a day continuously for 2 weeks orally. It was assessed that Diclofenac potassium was significantly better in the outcomes i n comparison to the trial drugs Commiphora wightii ( Guggulu ) and Curcuma longa ( Haridra ) when compar ed at the end of two weeks of start of the trial. Trial drugs Commiphora wightii ( Guggulu) and Curcuma longa ( Haridra) are also having outcomes of comparative extent to Diclofenac Potassium w hen administered continuously for further 6 weeks i.e. total 8 we eks.

Clinically relevant biomechanics of the knee capsule and ligaments.

The paper describes the concepts of primary and secondary restraints to knee joint stability and explains systematically how the tibia is stabilised against translational forces and rotational torques in different directions and axes, and how those vary across the arc of flexion-extension. It also shows how the menisci act to stabilise the knee, in addition to load carrying across the joint. It compares the properties of the natural stabilising structures with the strength and stiffness of autogenous tissue grafts and relates those strengths to the strength of graft fixation devices. A good understanding of the biomechanical behaviour of these various structures in the knee will help the surgeon in the assessment and treatment of single and multi-ligament injuries.

Torsional stability of the femur after harvest of the medial femoral condyle corticocancellous flap.

Increasingly large segments of medial femoral condyle (MFC) corticocancellous flaps have been harvested for transfer. Biomechanical evaluations demonstrated no osseous stability impairment under axial loading regardless of flap size harvested. The purpose of this study was to determine the donor site's response to torsional forces. Dual-energy X-ray absorptiometry (DEXA) scanning was performed on 16 pairs of cadaver legs followed by removal of all soft tissues, except knee capsule and ligaments. Specimens were randomly assigned to three groups with bone harvest defects measuring 3, 5, or 7 cm in length and a control group with no osseous resection. Torsional load was applied until fracture or ligamentous failure. Bone failure rates were 12.5, 12.5, 28.6, and 55.6% for control, 3, 5, and 7 cm groups, respectively. Bone failure rate increased with increasing harvest size; the 7 cm group demonstrated a significantly higher rate compared with the other groups combined (55.6 vs. 17.4%; p = 0.03). Failure torque was 45.5, 29.35, 27.4, and 30.83 Nm for the control, 3, 5, and 7 cm groups, respectively (p = 0.11). Harvest of any size segment resulted in a significant decrease in failure torque (p = 0.01). Bone mineral density (BMD) and Z-scores were no different among groups (p = 0.79 and 0.59, respectively). A direct relationship was identified between force required for failure and BMD (p = 0.02) and Z-scores (p = 0.05) but not for failure location and BMD (p = 0.09) or Z-scores (p = 0.94). MFC corticocancellous flap harvest of any size decreases donor site failure torque. Flap harvests > 7 cm demonstrate a higher frequency of iatrogenic fracture and therefore warrant caution with torsional loading of the knee postoperatively. Routine preoperative DEXA scans may not be warranted.

Innervation of the Anterior Capsule of the Human Knee: Implications for Radiofrequency Ablation.

Chronic knee pain is common in all age groups. Some patients who fail conservative therapy benefit from radiofrequency neurotomy. Knowledge of the anatomy is critical to ensure a successful outcome. The purpose of this study was to reanalyze the innervation to the anterior knee capsule from the perspective of the interventional pain practitioner. The study included a comprehensive literature review followed by dissection of 8 human knees to identify the primary capsular innervation of the anterior knee joint. Photographs and measurements were obtained for each relevant nerve branch. Stainless-steel wires were placed along the course of each primary innervation, and radiographs were obtained. Literature review revealed a lack of consensus on the number and origin of nerve branches innervating the anterior knee capsule. All dissections revealed the following 6 nerves: superolateral branch from the vastus lateralis, superomedial branch from the vastus medialis, middle branch from the vastus intermedius, inferolateral (recurrent) branch from the common peroneal nerve, inferomedial branch from the saphenous nerve, and a lateral articular nerve branch from the common peroneal nerve. Nerve branches showed variable proximal trajectories but constant distal points of contact with femur and tibia. The inferolateral peroneal nerve branch was found to be too close to the common peroneal nerve, making it inappropriate for radiofrequency neurotomy. The innervation of the anterior capsule of the knee joint seems to follow a constant pattern making at least 3 of these nerves accessible to percutaneous ablation. To optimize clinical outcome, well-aligned radiographs are critical to guide lesion placement.

Material properties of the human posterior knee capsule.

There is considerable interest to develop accurate subject-specific biomechanical models of the knee. Most of the existing models currently do not include a representation of the posterior knee capsule. In order to incorporate the posterior capsule in knee models, data is needed on its mechanical properties. To quantify the mechanical properties of the human posterior knee capsule through semi-static tensile tests. Fifteen posterior knee capsule specimens (5 knees, 3 male, 2 female; age 79.2±7.9 years) were used to perform tensile tests. A medial, central and lateral specimen was taken from each knee. The cross-sectional area was measured, after which semi-static tensile tests were performed to quantify the material properties. The stiffness of the capsule was randomly distributed over the regions. The global Young's modulus and yield strength was 8.58±10.77 MPa and 1.75±1.89 MPa, respectively. A strong correlation (ρ=0.900) was found between Young's modulus and yield strength. The location of failure was not associated with smallest cross-sectional area or highest strain. The results suggest that the posterior knee capsule does not have a systematic (medial-central-lateral) distribution of material properties. The posterior capsule may play an important role in knee joint mechanics, particularly when in hyper extension.

Knee Flexion Contractures in Patients with Osteoarthritis: Clinical Features and Histologic Characterization of the Posterior Capsule

ObjectiveTo (1) identify demographic and clinical factors associated with knee flexion contracture (KFlC) in the setting of osteoarthritis (OA) and (2) histologically compare the posterior knee capsule of patients with OA with and without KFlC. DesignCross-sectional study. SettingPrimary care, including private and institutional practice. PatientsThirteen patients with primary OA and KFlC and 8 patients with primary OA without KFlC. MethodsWe compared the KFlC and non-KFlC groups to identify demographic and clinical factors associated with KFlC. We examined the histology of the posterior knee capsules of 9 patients with KFlC and 6 without. Main Outcome MeasurementsPatient demographic and clinical factors. For histology we measured the proportional composition of collagenous, adipose, and synovial tissues; fibroblast and adipocyte cellularity; and synovial thickness. ResultsPatients with contracture had longer duration of OA, reduced flexion of the surgical knee, and reduced extension of the contralateral knee (P = .04, <.01, and <.01 respectively). Histologically, there was a greater proportion of collagenous tissue and a lower proportion of adipose and synovial tissues in the contracture group than in the noncontracture group; however, the differences were not statistically significant. Cellularity was similar between the 2 groups. ConclusionsLonger duration of knee OA, reduced surgical knee flexion, and reduced contralateral, nonsurgical knee extension were associated with KFlC in the OA knee undergoing total arthroplasty. Monitoring bilateral knee range of motion in patients with longer-duration OA could allow earlier intervention, reducing functional loss. Capsular tissue composition analysis may indicate a fibrotic disease process. Further research in which a larger sample size is used will help clarify these novel findings.

The adductor canal catheter and interspace between the popliteal artery and the posterior capsule of the knee for total knee arthroplasty

Analgesia for total knee arthroplasty (TKA) is not a new topic; however, some newer approaches to peripheral nerve blocks for control of postoperative pain have been developed. The femoral nerve block plus or minus a sciatic nerve block has been shown to provide effective analgesia, but not without some degree of motor block. The adductor canal block provides analgesia not inferior to a femoral with less motor weakness, and a continuous catheter technique can be used to prolong its effects. Blocking the sciatic nerve has been a subject of controversy, in part because of the motor weakness but also because of the inclusion of the common peroneal nerve, a nerve that can potentially be damaged by TKA. An infiltration of the interspace between the popliteal artery and the capsule of the posterior knee, provides analgesia for the posterior knee without motor effects or common peroneal block. The combination of an adductor canal catheter and an interspace between the popliteal artery and the capsule of the posterior knee provides a balance of effective postoperative analgesia and preservation of motor function, ultimately shortening length of stay following TKA.

Releasing the circumferential fixation of the medial meniscus does not affect its kinematics.

Meniscal functioning depends on the fixation between the meniscal horns and the surrounding tissues. It is unknown, however, whether the integration between the outer circumference of the medial meniscus and the knee capsule/medial collateral ligament also influences the biomechanical behavior of the meniscus. Therefore, we aimed to determine whether detaching and resuturing the circumferential fixation of the medial meniscus influence its kinematic pattern. Human cadaveric knee joints were flexed (0°-30°-60°-90°) in a knee loading rig, in neutral orientation and under internal and external tibial torques. Roentgen stereophotogrammetric analysis was used to determine the motion of the meniscus in anteroposterior (AP) and mediolateral (ML) directions. Three fixation conditions were evaluated: (I) intact, (II) detached and (III) resutured. Detaching and resuturing the circumferential fixation did not alter the meniscal motion pattern in either the AP or ML direction. Applying an additional internal tibial torque caused the medial meniscus to move slightly anteriorly, and an external torque caused a little posterior translation with respect to the neutral situation. These patterns did not change when the circumferential fixation condition was altered. This study demonstrated that the motion pattern of the medial meniscus is independent of its fixation to the knee capsule and medial collateral ligament. The outcomes of this study can be deployed to design the fixation strategy of a permanent meniscus prosthesis. As peripheral fixation is a complicated step during meniscal replacement, the surgical procedure is considerably simplified when non-resorbable implants do not require circumferential fixation.

Knee Evaluations

Knee Evaluations

Exploratory biomarker analysis reveals a genetic epistatic interaction in interleukin 1 receptor antagonist (IL1RN) gene associated to cartilage volume growth measured by MRI in response to sprifermin therapy in patients with knee radiographic osteoarthritis

Exploratory biomarker analysis reveals a genetic epistatic interaction in interleukin 1 receptor antagonist (IL1RN) gene associated to cartilage volume growth measured by MRI in response to sprifermin therapy in patients with knee radiographic osteoarthritis

MATERIAL PROPERTIES OF THE HUMAN POSTERIOR KNEE CAPSULE

BACKGROUND: There is considerable interest to develop accurate subject-specific biomechanical models of the knee. Most of the existing models currently do not include a representation of the posterior knee capsule. In order to incorporate the posterior capsule in knee models, data is needed on its mechanical properties. OBJECTIVE: To quantify the mechanical properties of the human posterior knee capsule through semi-static tensile tests.METHODS:Fifteen posterior knee capsule specimens (5 knees, 3 male, 2 female; age 79.2±7.9 years) were used to perform tensile tests. A medial, central and lateral specimen was taken from each knee. The cross-sectional area was measured, after which semi-static tensile tests were performed to quantify the material properties. RESULTS: The stiffness of the capsule was randomly distributed over the regions. The global Young’s modulus and yield strength was 8.58 ± 10.77 MPa and 1.75 ± 1.89 MPa, respectively. A strong correlation (ρ = 0.900) was found between Young’s modulus and yield strength. The location of failure was not associated with smallest cross-sectional area or highest strain. CONCLUSIONS: The results suggest that the posterior knee capsule does not have a systematic (medial–central–lateral) distribution of material properties. The posterior capsule may play an important role in knee joint mechanics, particularly when in hyper extension.

Proximaler Tibiaersatz und alloplastische Rekonstruktion des Streckapparats nach Resektion kniegelenksnaher Tumoren

The goal of the operation is limb-sparing resection of tumors arising from the proximal tibia with adequate surgical margins and local tumor control. Implantation of a constrained tumor prosthesis with an alloplastic reconstruction of the extensor mechanism to restore painless joint function and loading capacity of the extremity. Primary bone and soft tissue sarcomas. Benign or semimalignant aggressive lesions. Metastatic disease (radiation resistance and/or good prognosis). Poor physical status. Extensive metastatic disease with life expectancy <6months. Tumor penetration through the skin. Local infection or recalcitrant osteomyelitis. Poor therapeutic compliance. Large popliteal extraosseous tumor masses with infiltration of neurovascular structures. A single incision is made from the anteromedial aspect of the distal femur to the distal one third of the medial lower leg. Preparation of large medial and lateral fasciocutaneous flaps. The popliteal vessels are explored through a medial approach by releasing the pes anserinus and semimembranosus tendon, mobilizing the medial gastrocnemius muscle and detaching the soleus muscle from the tibial margo medialis. The anterior tibial artery and vein are ligated. If the knee joint is free of tumor, circumferential dissection of the knee capsule is performed and the patellar ligament is dissected. An osteotomy of the tibia shaft is performed with safety margins according to preoperative planning. In order to obtain adequate surgical margins, in some cases an enbloc resection of the tibiofibular joint becomes necessary. Therefore, the peroneal nerve is exposed. Parts of the M. tibialis anterior, a portion of the M. soleus and the entire M. popliteus are left on the resected tibial bone. After implantation of the prosthesis and coupling of the femoral and tibial component, the extensor mechanism is reconstructed using an alloplastic cord. It is passed transversely through the distal end of the quadriceps tendon looping the proximal margin of the patella. Both ends are passed distally through a subsynovial tunnel and are fixed under adequate pretension in a metal block of the tibial component. The detached hamstrings and remaining ligaments can be fixed on preformed eyes of the prosthesis. A medial gastrocnemius muscle flap is used to provide soft tissue coverage of the tibial component. Immobilization and elevation of the extremity for 5days, then flap conditioning. Mobilization in a hinged knee brace locked in extension for 6weeks without weight bearing. During this time active flexion with a stepwise progress, isometric quadriceps training. Then beginning of straight leg raising exercises, stepwise unlocking of the brace with 30° every 2weeks. Weight-bearing is increased by 10kg/week. Thrombosis prophylaxis until full weight-bearing. At follow-up, patients are monitored for local recurrence and metastases using history, physical examination and radiographic studies. Between 1988 and 2009, endoprosthetic replacement and alloplastic reconstruction of the extensor mechanism after resection of tibial bone tumors was performed in 17consecutive patients (9females and 8males) with a mean age of 31.1years (range 11-65years). There were no local recurrences. Until now, 5patients have died of tumor disease. One or more operative revisions were necessary in 53.9% of the patients. According to Kaplan-Meier survival analysis, the implant survival at 5years was 53.6% and 35.7% at 10years, respectively. In 2cases, a distal transfemoral amputation had to be performed due to deep infection. There were 3cases of tibial stem revision due to implant failure and aseptic loosening, respectively. In 3patients, the hinge of the prosthesis had to be revised. Impaired wound healing occurred in 2cases. Peroneal nerve palsy was observed in 3patients with recovery in only one. The mean Oxford knee score for 9of the 12living patients was 30.7 ± 7.5 (24-36). No patient had a clinically relevant extension lag. The mean range of motion at the last follow-up was 90.2° ± 26.7 (range 35-130°). All patients were well satisfied with their postoperative outcomes.

BMP-2 Dependent Increase of Soft Tissue Density in Arthrofibrotic TKA

Arthrofibrosis after total knee arthroplasty (TKA) is difficult to treat, as its aetiology remains unclear. In a previous study, we established a connection between the BMP-2 concentration in the synovial fluid and arthrofibrosis after TKA. The hypothesis of the present study was, therefore, that the limited range of motion in arthrofibrosis is caused by BMP-2 induced heterotopic ossifications, the quantity of which is dependent on the BMP-2 concentration in the synovial fluid.Eight patients with arthrofibrosis after TKA were included. The concentration of BMP-2 in the synovial fluid from each patient was determined by ELISA. Radiologically, digital radiographs were evaluated and the grey scale values were determined as a measure of the tissue density of defined areas. Apart from air, cutis, subcutis and muscle, the soft-tissue density in the area of the capsule of the suprapatellar pouch was determined. The connection between the BMP-2 concentration and the soft-tissue density was then investigated.The average BMP-2 concentration in the synovial fluid was 24.3 ± 6.9 pg/ml. The density of the anterior knee capsule was on average 136 ± 35 grey scale values. A linear correlation was shown between the BMP-2 concentration in the synovial fluid and the radiological density of the anterior joint capsule (R=0.84, p = 0.009).We were able to show that there is a connection between BMP-2 concentration and soft-tissue density in arthrofibrosis after TKA. This opens up the possibility of conducting a prophylaxis against arthrofibrosis in risk patients by influencing the BMP-2 pathway.

Long term followup of fresh osteochondral allografting of the femoral condyle

Long term followup of fresh osteochondral allografting of the femoral condyle

Immobilization induced prolonged inflammatory conditions in rat knee capsule

Purpose: Joint immobilization often induces joint stiffness, however, it is performed in daily examination in orthopaedics. Recent studies suggested that the joint capsule was one of the main sources of joint stiffness. In our previous reports, joint immobilization in rat knee joints induced increased stiffness of the capsule, and up-regulated gene and protein expressions in the capsule of fibrotic factors, such as TGF-b1 and CTGF. Though the precise etiology of joint stiffness has been still unknown, prolonged inflammation is one of the possible causes. In this study, we examined the histological changes of the capsule and expression of inflammatory cytokines by quantitative PCR and immunohistochemistry. Methods: Experimental Design: Unilateral knee joints were immobilized at 150 of flexionwith a plastic plate andmetal screws for1, 3 days,1, 2, 4, 8, 16 weeks. Only screws were inserted for sham-operated rats. The immobilized rats and sham-operated rats made up the immobilized group and the control group, respectively. One hundred and twelve ratswereprepared for histological analysis (n 1⁄4 8/each period). Thirty rats were prepared for quantitative PCR (1 day, 1 week, and 4 weeks; n 1⁄4 5/each period). Histology & Immunohistochemistry: The rats were fixed with 4% PFA in 0.1M PBS and the resected knee joints were decalcified in 10% EDTA in 0.01M PBS and embedded in paraffin. Five-mm sections were obtained at the medial mid-condylar region of the knee in the sagittal plane. The sections were stained with Elastica-Masson and the number of cells per unit in the capsule was counted. The sections were stained with rabbit anti-rat IL-6 antibody (Abcam, ab6672) and rabbit anti-rat IL-1b (Ab Frontier, LF-PA50204), and the expression patterns in the capsule were examined. Quantitative PCR: The anterior and posterior capsule were harvested and immediately placed in 1 ml QIAzol (Qiagen). The tissue was homogenized, the total RNAwas purified (RNeasy Lipid Tissue Kit, Qiagen), and the cDNA was synthesized (cDNA Synthesis Kit, Invitrogen). The relative expression levels of IL-6, IL-1a, IL-1b, TNF-a, and TNF-b as a function of EF1a1 was calculated. Results: Histology: The number of cells in the control groups was almost unchanged throughout the experimental periods. The number of cells at 1 daywasnot changed, however, thenumberat 3 dayswas significantly higher in the immobilized group. The number of cells in the immobilized groups peaked at 3 days and then gradually decreased after 1 week. Immunocytochemistry: The staining intensity of IL-6 in the capsule was weak at 1 day, however, the intensitywas stronger at 3 days in the two groups. The staining intensity in the control groups peaked at 3 days, and decreased after 1week. The strong staining intensity in the immobilized groups was kept until 4 weeks, and then became weaker at 8 weeks. The staining intensity of IL-1b was similar fashion to IL-6. Quantitative PCR: Increased expression of IL-6 was observed at 1 day in the two groups. The expression levels in the control groups were normalized after 1 week, whereas, the expression levels in the immobilized groups were kept higher level at 1 week. Conclusions: The prolonged inflammatory conditions were kept in the joint capsule after immobilization. Increased number of cells in the immobilized group may support the results. It was indicated that prolonged inflammation and subsequent fibrosis of the joint capsule was a main pathology of the joint contracture after immobilization.

The role of the elastic fiber system in the pathogenesis of osteoarthritis and knee joint laxity

Osteoarthritis (OA) is a disease of synovial joints in which all articular structures are affected. Evidence suggests that a decreased density in the elastic fiber concentration of the knee capsule is associated with joint hypermobility, a condition associated with OA. However, there is no study that shows a direct relationship between the elastic fiber system and knee OA. The purpose of this study is to determine if there is a correlation between the elastic fiber density in medial (MCL) and lateral (LCL) collateral ligaments and the severity of OA. The elastic fiber concentration in MCL and LCL were examined in cadaver knees (n = 10; 4 M, 6 F). The elastic fiber density, measured as the concentration of elastic fibers per unit area, was correlated with the severity of OA, which was graded on a 0-16 scale using histologic and macroscopic markers. Among all subjects, elastic fiber concentrations between MCL (mean 15.49% ± 2.49) and LCL (mean 13.93 ± 3.63) showed a significant difference (P = 0.023). There were no inter-gender differences between the elastic fiber concentration in either MCL or LCL. Among all subjects, the severity of OA was found to be correlated negatively with the elastic fiber concentration in both MCL (r = -0.693, P ≤ 0.05) and LCL (r = -0.718, P ≤ 0.05). This is the first study to show a correlation between the elastic fiber system and knee OA.

A randomised controlled trial investigating the effect of posterior capsular stripping on knee flexion and range of motion in patients undergoing primary knee arthroplasty

Increasing knee flexion following total knee arthroplasty (TKA) has become an important outcome measure. Surgical technique is one factor that can influence knee motion. In this study, it was hypothesised that stripping of the posterior knee capsule could improve flexion and range of motion (ROM) following TKA. Patients who were undergoing TKA were prospectively randomised into two groups — one group (62 patients) were allocated stripping of the posterior knee capsule (PCS), the other group (66 patients) no stripping (no-PCS). The primary outcome was change in flexion and ROM compared to pre-operative measurements at three time points; after wound closure, 3 months and 1 year post-operatively. Secondary outcomes were absolute measurements of flexion, extension, ROM and complications. All operations were performed by a single surgeon using the same implant and technique. All patients received identical post-operative rehabilitation. There was a significant gain in flexion after wound closure in the PCS group ( p = 0.022), however there was no significant difference at 3 months or 1 year post-operatively. Absolute values of extension ( p = 0.008) and flexion ( p = 0.001) 3 months post-operatively were significantly reduced for the PCS group. The absolute value of ROM was significantly higher for the no-PCS group at 3 months ( p = 0.0002) and 1 year ( p = 0.005).There were no significant difference in the rate of complications. Posterior capsular stripping causes a transient increase in flexion that does not persist post-operatively. We do not recommend routine stripping of the posterior knee capsule in patients undergoing TKA.

Reply to the comments by Dr. Özer et al. on our article “Anatomic double-bundle ACL reconstruction with femoral cortical bone bridge support using hamstrings”

Dear Editor, We would like to thank Dr. Ozer et al. for the comments regarding our article ‘‘Anatomic double-bundle ACL reconstruction with femoral cortical bone bridge support using hamstrings’’ [4]. We shall attempt to answer each of them in turn. We do, indeed, create the femoral tunnels using the outside-in technique via a small incision (1.5–2 cm) on the lateral femoral epicondyle, a procedure which in no way affects the posterior knee capsule. In our experience, neither the ACL technique outlined in the article, nor another that we used previously in which the femoral tunnels were also created via the outside-in technique [3] have led to any morbidity that could be attributed to the use of said method. The k-wires are inserted via the femoral lateral epicondyle, either at the same angle as the frontal plane of the femur or gently inclined from front to back, and in a slightly craniocaudal direction, entering the joint via the previously-located insertion points on the two ACL bundles (4–5 mm distal to the over the top position and posterior to the roof of the notch in the case of the AM bundle and 9–10 mm distal to the AM bundle and 4–5 mm anterior to the posterior margin of the articular cartilage of the lateral femoral condyle for its PL counterpart). We agree that chamfering the edges of the tunnels may reduce graft friction; however, we have never experienced any problems of this nature either. Though our earlier method [3] resolved the problem in question, one of our main concerns while developing our current technique was that the graft might be too short. We therefore measured the graft and calculated the length required for reconstruction (Table 1 shows that in all cases, the length used was more than sufficient). With regard to graft thickness, it is true that when hamstrings are used, one end of the graft is thinner than the other due to its tendofascial structure. The end in question, however, is the one whose length exceeds that required and will ultimately be cut in any case. As for the thickness of the AM bundle, we concur with other authors [1, 2, 5] that 6–7 mm is sufficient, especially if we take into account that we are performing an anatomical double-bundle reconstruction in which stability is guaranteed by both bundles. We also agree that the fixation screw used should be as long as possible; however, the longest available is 30 mm. The maximum length of the ones used in our technique (Biosteon, Stryker Endoscopy San Jose, CA) for diameters of less than 9 mm is 28 mm. Finally, we concur that increased fixation may be achieved by inserting a further screw in the PL tunnel.

The effects of thermal capsulorrhaphy of medial parapatellar capsule on patellar lateral displacement

BackgroundThe effectiveness of thermal shrinkage on the medial parapatellar capsule for treating recurrent patellar dislocation is controversial. One of reasons why it is still controversial is that the effectiveness is still qualitatively measured. The purpose of this study was to quantitatively determine the immediate effectiveness of the medial parapatellar capsule shrinkage as in clinical setting.MethodsNine cadaveric knees were used to collect lateral displacement data before and after medial shrinkage or open surgery. The force and displacement were recorded while a physician pressed the patella from the medial side to mimic the physical exam used in clinic. Ten healthy subjects were used to test the feasibility of the technique on patients and establish normal range of lateral displacement of the patella under a medial force. The force applied, the resulting displacement and the ratio of force over displacement were compared among four data groups (normal knees, cadaveric knees before medial shrinkage, after shrinkage and after open surgery).ResultsDisplacements of the cadaveric knees both before and after thermal modification were similar to normal subjects, and the applied forces were significantly higher. No significant differences were found between before and after thermal modification groups. After open surgery, displacements were reduced significantly while applied forces were significantly higher.ConclusionNo immediate difference was found after thermal shrinkage of the medial parapatellar capsule. Open surgery immediately improved of the lateral stiffness of the knee capsule.

Men versus Women

The role played by femoral component sizing in the clinical outcome of primary TKA is currently debated. Oversizing the femur in patients with smaller knees could lead to overstuffing the knee capsule with resulting pain and reduced range of motion. We asked whether the distribution of femoral component sizes differed between genders and whether the availability of additional sizes benefited genders differently and led to a measurable improvement in knee flexion and Knee Society scores or pain. We retrospectively examined two groups of consecutive knees of patients who underwent primary TKA using similar techniques and constraint: Group 1 (93 men and 90 women) who had available four original sizes and Group 2 (106 men and 106 women) after the introduction of three new smaller sizes. More than twice as many new smaller sizes were used in women (52.3%, 56 of 106) compared to men (17.9%, 19 of 106). At the scheduled 6-month followup visit (average, 6 months; range, 5-7 months), we found no differences in the knee score, pain score, and knee flexion in men and women before the additional sizes (Group 1) and after the new sizes (Group 2). Additional sizes therefore did not appear to influence short-term outcomes. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.