Total knee replacement for posttraumatic degenerative arthritis of the knee

Althoughsignificantadvancehasbeenmadeinoperativetreatmentofkneefracturesoverthelasttwodecades,fracturesofthedistalfemurorproximaltibiastillmayleadtoposttraumatic arthritis.13Concomitantly,markedimprovementin totalkneearthroplasty(TKA)hasalsobeenmade durin…     

Single incision nailing of the floating knee—do we ignore the knee ligaments?

The incidence of knee ligament injuries in the floating knee is as high as 53% documented in the literature. The single incision technique (antegrade tibial and retrograde femoral nailing through a single incision at the knee) although a good technique in terms of speed and ease, has its own disadvantages. Repair or reconstruction of a torn anterior or posterior cruciate ligament after a single incision technique can be a difficult proposition. Antegrade femoral and tibial nailing (two incisions) makes treatment of knee ligament injuries easier.This comment refers to the article available at: .     

Arthroscopy prior to osteotomy around the knee?

Introduction  Osteotomy around the knee is well established in orthopaedic surgery in cases of congenital/posttraumatic leg deformities with mono-compartment osteoarthritis of the knee. However, there is no consensus whether there should be an arthroscopy prior to osteotomy in the same operative session, either for diagnostic or therapeutic reasons. Patients and methods  This prospective study included 340 cases of osteotomy around the knee with a routine arthroscopy. During arthroscopy indication for osteotomy was checked first. Then cartilage status was determined to modify type and degree of correction osteotomy accordingly. Finally therapeutic procedures were performed in cases of intraarticular pathologies. Results  Indication was rejected in 47 cases with ten patients receiving endoprosthetic treatment. In 157 cases the degree of correction was modified, in eleven cases the level of osteotomy. Under the 330 non-endoprothetic sessions there were 316 arthroscopies with therapeutic treatments. Conclusion  This study could demonstrate that arthroscopy in the same session is indispensable, to check the indication for osteotomy, to modify type and degree of correction according to cartilage status and to perform therapeutic procedures.     

Periprosthetic fractures around the knee—the best way of treatment

Background

A variety of methods has been described to stabilise periprosthetic fractures around total knee arthroplasty (TKA). Our report offers a review of the actual strategies in the reduction and fixation of these fractures. Surgical treatment should be based on the following four steps:

1. Diagnostics: By taking the patients' history together with an X-ray of the knee and femur, the fracture is analysed. It is crucial to define whether any losening of the prosthesis had occurred. In selected cases, CT-scan may add important information on the stability of the implant.
2. Classification and planning: For most fractures around the distal femur, the Rorabeck classification is used while fractures around the proximal tibia are best classified according to the Felix classification. Additionally the Orthopaedic Trauma Association (OTA) may be helpful in the planning process for reduction and fixation.
3. Surgigal technique: In fractures around a stable implant (Rorabeck type I and II; Felix type A and C), it is favourable to use plates and retrograde nails (in Rorabeck I or II with an open box of a TKA). For reduction, three methods are available: (a) the open technique (with direct or indirect reduction); (b) the mini open technique (direct reduction of the fracture by cerclage or lag screw and percutaneous plate fixation in OTA type 32 or 33-A1) and (c) the minimally invasive technique (indirect reduction and percutaneous fixation in all other OTA types). Fractures with a loose prosthesis (Rorabeck III and Felix B) are best stabilised by hinged revision arthroplasty.
4. Rehabilitation: It is of great importance for the aged patient to be mobilised out of bed early. In most of the cases, partial weight bearing has to be performed by the aid of frames during the first 6 weeks after surgery. In a well-fixed revision prosthesis with a cemented stem, early full weight bearing might be allowed.

Conclusion

Standardised less invasive procedures to treat periprosthetic fractures present a valuable alternative to open techniques. The main advantages are lower rates of oft tissue complications and implant failures following less invasive techniques of long plate application. Polyaxial locking systems allow for stable plate fixation around intramedullary implants.     

Recovery of knee function in the isolated MCL and combined ACL–MCL deficient knee

Background

The MCL is the prime medial stabiliser of the knee and is a commonly injured structure which leads to valgus instability of the knee.

Objectives

We aim to analyse differences in recovery of knee motion and muscle function over one year follow up in the isolated MCL and combined ACL–MCL injured knee. We hypothesized that combined ACL–MCL injuries lead to greater knee motion and muscle function deficits at 1 year.

Methods

Isolated MCL (Group I) or combined ACL–MCL injuries (Group II) from 2006–2010 were included. Those with a previous MCL injury, injury to contralateral limb or presenting 2 weeks post-injury were excluded. At certain outpatient follow up intervals, we recorded pre-determined parameters of knee function. Follow-up was at weeks 2, 6, 12, 26, 52.

Results

The cohort included 82 patients (54 males:28 females) with a mean age of 32 (range 16–56). Group II showed a deficit in Total Range of Movement (TROM) and flexion at 6 month follow up (p < 0.05). Group II showed an extension deficit at week 2 (p < 0.05). The Peak Torque Deficit (PTD) and Average Power Deficit (APD) improved for quadriceps and hamstrings across all follow up intervals (p > 0.05).

Conclusion

There is a TROM and flexion deficit at 6 months in group II, resolving by 1 year. There was no difference in PTD or APD in either group.     

Does knee position at the time of tourniquet inflation affect knee range of motion?

Pneumatic tourniquets about the thigh are commonly employed in lower extremity orthopaedic surgery to maintain a bloodless operative field. The purpose of this study was to determine whether the position of the knee at the time of tourniquet inflation has an impact on knee range of motion (ROM). Passive ROM of the knees of 30 patients was measured with the tourniquet deflated, with the tourniquet inflated while the knees were in extension, and with the tourniquet inflated while the knees were in flexion. The average knee ROM with a deflated tourniquet was 143.0 degrees with a standard deviation of 8.1 degrees (range, 125 degrees -160 degrees ). When the tourniquet was inflated with the knees in extension, the average knee ROM was 143.0 degrees with a standard deviation of 7.8 degrees (range, 125 degrees -159 degrees ). When the tourniquet was inflated with the knees in flexion, the average knee ROM was 143.7 degrees with a standard deviation of 7.8 degrees (range, 124 degrees -160 degrees ). There was a statistically significant difference between the ROM of knees with tourniquet inflation in flexion versus extension (p = .0011.) Although there was a statistical difference, it was concluded that a difference of approximately 1 degrees in knee ROM is not clinically relevant.     

How does laxity after single radius total knee arthroplasty compare with the native knee?

Patients with total knee arthroplasties (TKAs) continue to report dissatisfaction in functional outcome. Stability is a major factor contributing to functionality of TKAs. Implants with single‐radius (SR) femoral components are proposed to increase stability throughout the arc of flexion. Using computer navigation and loaded cadaveric legs, we characterized the “envelope of laxity” (EoL) offered by a SR cruciate retaining (CR)‐TKA compared with that of the native knee through the arc of flexion in terms of anterior drawer, varus/valgus stress, and internal/external rotation. In both the native knee and the TKA laxity increased with increasing knee flexion. Laxities measured in the three planes of motion were generally comparable between the native knee and TKA from 0° to 110° of flexion. Our results indicate that the SR CR‐TKA offers appropriate stability in the absence of soft tissue deficiency. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1208–1213, 2014.     

Investigating the effects of anterior tibial translation on anterior knee force in the porcine model: Is the porcine knee ACL dependent?

This study sought to determine anterior force in the porcine knee during simulated 6‐degree‐of‐freedom (DOF) motion to establish the role of the anterior cruciate ligament (ACL). Using a 6‐DOF robot, a simulated ovine motion was applied to porcine hind limbs while recording the corresponding forces. Since the porcine knee is more lax than the ovine knee, anterior tibial translations were superimposed on the simulated motion in 2 mm increments from 0 mm to 10 mm to find a condition that would load the ACL. Increments through 8 mm increased anterior knee force, while the 10 mm increment decreased the force. Beyond 4 mm, anterior force increases were non‐linear and less than the increases at 2 and 4 mm, which may indicate early structural damage. At 4 mm, the average anterior force was 76.9 ± 10.6 N (mean ± SEM; p < 0.025). The ACL was the primary restraint, accounting for 80–125% of anterior force throughout the range of motion. These results demonstrate the ACL dependence of the porcine knee for the simulated motion, suggesting this model as a candidate for studying ACL function. With reproducible testing conditions that challenge the ACL, this model could be used in developing and screening possible reconstruction strategies. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:641–646, 2011     

A broken sewing needle in the knee of a 4-year-old child: is it really inside the knee?

We report on a case of a broken needle that migrated inside the knee joint of a 4-year-old girl. Searching for any small foreign body in the knee joint is not easy in either open or arthroscopic procedures. In this case, the surgery was made more difficult because of technical delays and diagnostic difficulties in defining the surgical plane of the needle. Arthroscopic expertise and some basic precautions can minimize the morbidity to a young patient and prevent migration into the knee joint proper.     

Prevalence and characteristics of unilateral knee osteoarthritis in a community sample of elderly Japanese: do fractures around the knee affect the pathogenesis of unilateral knee osteoarthritis?

BackgroundThe purpose of this study was to investigate the prevalence and characteristics of unilateral knee osteoarthritis (KOA), to investigate what percent of contralateral healthy knees in patients with unilateral KOA progress to KOA, and to investigate whether knee fractures influence unilateral KOA.MethodsStudies were performed every two years from 1997 to 2009 in Miyagawa village, for a total of seven studies. A total of 1239 village inhabitants aged ≥65 years participated in these studies at least once. KOA was defined as a Kellgren–Lawrence (K/L) grade ≥2. Based on the knee X-ray at the first examination, participants were divided into three groups: no KOA (N group), unilateral KOA (U group), and bilateral KOA (B group). The U group was divided into two subgroups: K/L grade II-I combination (II-I group), and the U group without the II-I combination (G>2 group). To investigate whether knee fractures influence unilateral KOA, the fracture history was considered.ResultsThe percentages of participants classified into the N, B, and U groups (II-I and G>2 group) were 68.4, 21.6, and 10.0 % (7.8 and 2.1 %), respectively. Most of the U group had the II-I combination (78.7 %). The percentages of knee fractures in the N, B, II-I, and G>2 groups were 3.3, 5.3, 6.3, and 38.5 %, respectively. Overall, 49.2 % of the U group proceeded to bilateral KOA over an average of 5.3 years.ConclusionsThe prevalences of definite radiographic bilateral and unilateral KOA were 21.6 and 10.0 %, respectively. Overall, 49.2 % of the participants with unilateral KOA developed KOA in the contralateral knee over an average of 5.3 years. If bilateral KOA advanced simultaneously, the II-I group was considered to represent the midpoint of progression to bilateral KOA. Bilateral KOA advanced simultaneously except in cases with a history of knee trauma, such as fractures.     

Is extreme flexion of the knee after total knee replacement a prerequisite for patient satisfaction?

The focus of this study was to evaluate the functional result and to specifically ascertain whether the absence of the ability to squat and sit cross-legged altered the patient's satisfaction level after a successful standard total knee replacement. Squatting and sitting cross-legged are common practices in Asia. These activities are not possible following standard total knee replacement. Patients were followed-up for a minimum of 12 months post surgery. Their level of satisfaction was assessed using a Likert scale. The Knee Society Score (KSS) was used to assess range of motion and function of the knee. Twenty-one out of 25 patients were satisfied with the surgical result in spite of an inability to squat. Deep knee flexion may not be an essential prerequisite for patient satisfaction after total knee replacement, even in a population where squatting and sitting cross-legged are part of the normal lifestyle.     

Does mismatch of the femoral component aspect ratio influence the range of knee flexion after posterior-stabi- lized total knee arthroplasty？

Objective: To study whether the range of knee flexion (ROF) is affected by geometrical mismatch of the femoral component and the resultant change in the posterior condylar offset (PCO) after high-flexi...     

Arthroscopic débridement for osteoarthritis of the knee

BACKGROUND: The role of arthroscopic débridement in the treatment of osteoarthritis of the knee remains to be defined, and few clinical and radiographic characteristics have been quantitatively associated with the outcome. The hypothesis of this study was that the outcome of arthroscopic débridement for osteoarthritis of the knee is associated with preoperative clinical and radiographic features and intraoperative characteristics and that there are subsets of patients who are more and less likely to respond favorably to the treatment. METHODS: We performed a cross-sectional study of a consecutive cohort of 122 patients who underwent arthroscopic débridement for the treatment of osteoarthritis of the knee that had been unresponsive to anti-inflammatory therapy. One hundred and ten patients were followed for a mean of thirty-four months. Pain was assessed with the pain domain of the Knee Society scoring system. Radiographs were scored with the Kellgren-Lawrence method, and limb alignment and the widths of the medial and lateral joint spaces were measured. The severity of cartilage lesions was scored intraoperatively with a modified Noyes grading system. Specific methods of data collection and analysis were incorporated to minimize bias. RESULTS: Fifty-two (90%) of fifty-eight knees with mild arthritis, normal alignment, and a joint space width of > or = 3 mm were improved after arthroscopic débridement. Conversely, only five (25%) of twenty knees with severe arthritis, limb malalignment, and a joint space width of < 2 mm had substantial relief of symptoms. Of seventy-two patients who had improvement, forty-four (61%) had it within six months after the arthroscopy. The severity of the lesion was highly predictive of the clinical outcome both in patients with mild arthritis and in those with severe arthritis. CONCLUSIONS: The severity of the arthritis, as assessed preoperatively with radiography and intraoperatively by rating the severity of cartilage lesions, influences the clinical outcome of arthroscopic débridement of an osteoarthritic knee. Knees with severe arthritis fare poorly, whereas those with mild arthritis fare well. We could not predict the outcome for knees with moderate arthritis. We believe that these observations are relevant for establishing indications for arthroscopy in patients with osteoarthritis of the knee and may be useful for designing studies with a more rigorous experimental design.     

Can the gracilis replace the anterior cruciate ligament in the knee? A biomechanical study

Purpose

The purpose of this study was to determine whether a four-strand gracilis-only construct possesses the biomechanical properties needed to act as an anterior cruciate ligament (ACL) reconstruction graft.

Methods

This was a pilot study with 32 cadaver specimens. The biomechanical properties of three types of grafts were determined using validated tensile testing methods: patellar tendon (BTB), both hamstring tendons together (GST4) and gracilis alone (G4).

Results

The maximum load at failure of the G4 was 416.4 N (±187.7). The GST4 and BTB had a maximum load at failure of 473.5 N (±176.9) and 413.3 N (±120.4), respectively. The three groups had similar mean maximum load and stiffness values. The patellar tendon had significantly less elongation at failure than the other two graft types.

Conclusions

The biomechanical properties of a four-strand gracilis construct are comparable to the ones of standard grafts. This type of graft would be useful in the reconstruction of the anteromedial bundle in patients with partial ACL ruptures.

     

Bilogic characteristics of fibroblast cells cultured from the knee ligaments

OBJECTIVE: To culture fibroblast cells from the knee ligaments and to study the biological characteristics of these cells. METHODS: Cells of the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) from New Zealand white rabbit were cultured in vitro. Cellular growth and expression of the collagen were analyzed. Moreover, an in vitro wound closure model was established and the healing of the ACL and the MCL cells was compared. RESULTS: Maximal growth for all these cells were obtained with Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, but RPMI 1640 and Ham's F12 media were not suitable to maintain these cells. Morphology of both ACL and MCL cells from New Zealand white rabbit was alike in vitro, but the MCL cells grew faster than the ACL cells. Both cell types produced similar amount of collagen in culture, but the ratio of collage type I to type III produced by ACL cells was higher than that produced by MCL cells. Wound closure assay showed that at 36 hours after injury, cell-free zones created in the ACL cultures were occupied partially by the ACL cells; in contrast, the wounded zone in the MCL cultures was almost completely covered by the cells. CONCLUSIONS: Although the ACL cells and the MCL cells from New Zealand white rabbit show similar appearance in morphology in culture, the cellular growth and the biochemical synthesis of collagen as well as the healing in vitro were significantly different. These differences in intrinsic properties of the two types of cells in vitro might contribute to the differential healing potentials of these ligaments in vivo.