Quadriceps-sparing versus mini-subvastus approach in total knee arthroplasty.

In a prospective randomized double-blind study we compared the postoperative recovery and early results of two groups of 30 patients having total knee arthroplasty with minimally invasive techniques using either a mini-subvastus or a modified "quadriceps-sparing" approach. All knees were implanted with the same posterior-stabilized prosthesis (LPS-Flex, Zimmer, Warsaw, IN) by the same surgeon with the same dedicated set of downsized instruments. Epidural anesthesia with the same postoperative analgesia and rehabilitation protocol was used in all patients. Evaluation was performed preoperatively, postoperatively in the first week, and at 1 and 3 months. In five cases in the "quadriceps- sparing" group, the incision was extended a few cm to facilitate exposure. Tourniquet time, estimated blood loss, and postoperative pain were similar in the two groups. Active straight leg raising was achieved half a day earlier, on average, in the mini-subvastus group (1.9 vs 1.4 days). Average maximum active flexion was similar in the two groups at each interval, and reached 117 degrees and 119 degrees at 3 months for the mini-subvastus and "quadriceps-sparing" group, respectively. We believe there was no difference between the mini-subvastus and "quadriceps-sparing" approach in relation to short term recovery or early results.

Mini-subvastus versus medial parapatellar approach in total knee arthroplasty.

UNLABELLED: We compared short-term clinical results of the mini-subvastus approach with the standard parapatellar approach for total knee arthroplasty. Can one gain adequate access through the mini-subvastus approach without exceeding operating time, incurring additional complications, and maintaining correct implant geometry? In a prospective, observer-blinded study, 120 consecutive patients having total knee arthroplasty were operated on by one surgeon using either the mini-subvastus approach without patella eversion or the standard parapatellar approach with patella eversion. Patients were matched according to age, gender, body mass index, knee flexion, deformity, and pre-existing high tibial osteotomy. The mini-subvastus approach was technically more demanding. Reduced access and visibility prolonged the tourniquet time by an average of 15 minutes and led to two intraoperative complications. Patients in the mini-subvastus group lost on average 100 mL less blood and had better pain scores on day one [visual analogue scale (VAS): mean 2.4 versus 3.89]. They reached 90 degrees knee flexion earlier (2.8 versus 4.5 days), and an active straight-leg raise earlier (3.2 versus 4.1 days). Their average flexion at 30, 60 and 90 days was slightly better (100 degrees , 110 degrees , and 112 degrees versus 94 degrees , 106 degrees , and 109 degrees ). All patients including those with complications had good results with good component geometry and leg alignment. The mini-subvastus approach offers early but short-lived benefits for patients at the expense of a longer operation and a higher risk of complications. LEVEL OF EVIDENCE: Therapeutic study, Level II-1 (prospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Flexion-extension gap changes during total knee arthroplasty: effect of posterior cruciate ligament and posterior osteophytes removal.

Flexion and extension gap heights were measured in 50 consecutive primary posterior-stabilized total knee arthroplasties (TKAs) to determine whether posterior cruciate ligament (PCL) release or re-establishment of the posterior condylar recess increased gap width. After PCL release, a slight symmetrical increase was noted in both gaps. In extension, gap width increased on average 1.3 mm and 1 mm in the medial and lateral compartments, respectively. The same pattern was observed in flexion, averaging 1.3 mm medially and 1.3 mm laterally. Another increase in the two gaps was observed after the posterior condylar osteophytes were removed and the posterior recess was re-established. The gaps in extension increased, with respect to the base-line value, on average 1.8 mm medially and 1.8 mm laterally, whereas flexion increased an average 2 mm medially and 2.2 mm laterally. No statistical differences were noted between flexion and extension gaps. No independent differences between the flexion and extension gaps were found in any surgical phase. Posterior cruciate ligament removal and re-establishment of posterior condylar recess does not require additional consideration in gap balancing during posterior-stabilized TKA.

Lateral collateral ligament reconstruction using a semitendinosus graft.

We evaluated 13 reconstructions of the lateral collateral ligament (LCL) of the knee associated with a reconstruction of the ACL (n=6) and PCL (n=7). In all cases the LCL was reconstructed using a semitendinosus tendon graft through a tunnel in the fibular head and fixed in anatomical insertion of LCL at lateral femoral condyle. Patients were evaluated using the IKDC form. Lateral joint opening and posterior tibial translation were studied by radiographic stress views. The follow-up average was of 60 months (38-93). In the ACL group five patient were symptoms free while one reported moderate pain after strenuous activity. The lateral stress radiographs showed lateral joint opening of 0-2 mm in five knees, and 3-5 mm in one. In the PCL group four patients were symptom free while three complained mild to moderate pain or swelling. Lateral joint opening was 0-2 mm in six knees and 3-5 in one. External rotation at 30 degrees of flexion was 10 degrees in one and between 0-5 degrees in the remainder. Eleven of 13 patients returned to their preinjury level and two returned to one level lower. These findings indicate that the LCL can be successfully reconstructed with a free ST graft at the time of ACL or PCL reconstruction.

Mobile and fixed bearing total knee prosthesis functional comparison during stair climbing.

OBJECTIVE: The purpose of this investigation is to determine the functional performance of the mobile bearing total knee replacement prosthesis as compared to the fixed bearing type total knee replacement prosthesis. DESIGN: Kinematics, kinetics, and electromyography data were gained from 10 patients with mobile bearing and 10 patients with a fixed bearing posterior stabilized Insall Burstein II total knee replacement during ascending and descending stairs. A control group of 10 normal subjects, matched by sex and age, was also analysed. BACKGROUND: No significant biomechanical differences in patients with different total knee replacement designs have been reported from level-walking studies. Slightly better performance of posterior retaining with respect to cruciate sacrificing total knee replacement designs have been claimed from stair climbing studies. Only one study has been conducted regarding mobile versus fixed bearing total knee replacement assessed by gait analysis. This study did not show any biomechanical differences between the two groups. METHODS: Motion analysis was used to quantify the knee kinematics, kinetics, and electromyography (right and left longissimus dorsi, gluteus medius, rectus femoris, biceps femoris, semitendinosus, gastrocnemius and tibialis anterior muscles) during stair ascent and descent. RESULTS: The mobile bearing group demonstrated a reduced knee extensor moment during stair climbing and descending, and a reduced knee adductor moment during stair climbing. When ascending stairs, most of the mobile bearing patients show a peak knee flexion and a peak knee flexion moment at the late stance phase during the double support period. This kinematic and kinetic pattern is absent in normal subject. Both mobile bearing and fixed bearing groups showed abnormal electromyography patterns in both descending and ascending. CONCLUSIONS: During stair climbing, the mobile bearing design demonstrates a different kinematic pattern to the fixed bearing total knee replacement. Lower limb compensatory mechanisms seemed to be adopted particularly by the mobile bearing patients during ascending stairs. RELEVANCE: Total knee replacement patient with mobile bearing design can feel excessive femoro-tibial motion during daily living activities such as stair climbing and descending. Proprioceptive control of this tibio-femoral translation is needed as demonstrated by the lower limb compensatory mechanism. This data suggest that antero-posterior constraint structures (ligamentous or mechanical) are important to obtain reproducible knee kinematics.

The Insall-Burstein II prosthesis: a 5- to 9-year follow-up study in osteoarthritic knees.

We prospectively studied 100 Insall-Burstein Posterior Stabilized II total knee arthroplasties (Zimmer Inc, Warsaw, IN) consecutively implanted in 91 patients with osteoarthritis. We reviewed 92 knees in 85 patients at a mean follow-up of 7.5 years (range, 5.3-9.5 years). According to the Knee Society score, 78 (85%) results were excellent, 11 (12%) were good, and 3 (3%) were fair or poor. The unsatisfactory results were attributed to patellofemoral pain with a low patella (2 knees) and to valgus alignment and medial laxity (1 knee). Flexion at follow-up averaged 116 degrees. Nonprogressive radiolucent lines were present around 30% of the tibial components. There was only 1 small osteolytic lesion around the tibial plateau. We observed no aspetic loosening, infection, or patella stress fracture. Survivorship analysis in the worst-case scenario showed a 90.9% success rate at 8 years.

Results of arthroscopic excision of the fragment in the treatment of osteochondritis dissecans of the knee.

PURPOSE: To evaluate clinical and radiological results of arthroscopic excision of the fragment and debridement of the crater in the treatment of osteochondritis dissecans of the knee (OCD). TYPE OF STUDY: Case series. METHODS: We investigated 20 patients with partial or complete detachment of the OCD fragment. The average age at surgery was 21 years (range, 12 to 32 years). All the patients were treated by the same surgeon. They were evaluated at an average follow-up of 9 years (range, 6 to 17 years). RESULTS: The combined subjective and objective evaluation showed excellent and good results for 85% of the patients. Radiographic studies showed 2 grades of worsening (from no degenerative signs preoperatively to narrowing of the joint line up to 50% at follow-up) in 1 patient (5%). One grade of worsening (Fairbank's changes without joint space narrowing) was found in 45% of weight-bearing anteroposterior radiographic views and in 35% of weight-bearing bent knee posteroanterior views. Statistical correlations were significant between radiographic degenerative changes and the size of the osteochondral lesion at surgery, with larger lesions resulting in greater degenerative changes. CONCLUSIONS: The arthroscopic removal of an osteochondral fragment and debridement of the crater is a viable option in the treatment of grade III and IV OCD lesions. Results are better in lesions less than 2 cm(2).

Patella resurfacing in total knee replacement: functional evaluation and complications.

Three different knee replacements, with three trochlear designs, were prospectively evaluated clinically and radiographically for patellar function and presence of patellar complications. They included the Insall-Burstein (IB) I and the IB-II (posterior cruciate ligament substituting) and the Meniscal Bearing Knee (MBK; posterior cruciate ligament recession). The trochlea of the IB-I was short and shallow with an anterior sharp edge of the intercondylar box (later modified to a smoother edge) and the femoral component had a prominent "shoulder." In the IB-II the trochlea was deeper to allow for soft tissue clearance. In the MBK the trochlea was more prolonged, with R and L components and the "shoulder" was less prominent. In all the cases the patella was resurfaced with an all polyethylene dome prosthesis. Knees with tibiofemoral problems were excluded. From the data of the present study the following conclusions can be drawn: (a) The most frequent problem was impingement (clunks) with the early version of the IB-I. Smoothening of the anterior edge significantly reduced the incidence of clunks to 5% in the modified IB I. (b) With the IB-II deepening the trochlea for soft tissue clearance improved the degree, not the incidence of clunks (4.5%), compared to the modified IB I. (c) With the MBK clunks were very rare and patellar function improved. (d) Throughout the three series patellar stress fractures and instability were rare and loosening or wear not evident. (e) Normal function (including stairs ascending and descending) can be expected in over 80% of category A patients. (f) Of the various radiological parameters only patella baja was correlated with symptoms in the IB prostheses. (g) We still prefer the dome design because is more tolerant and with cold flow may better conform to the trochlea increasing contact area.

Effect of tourniquet use on activation of coagulation in total knee replacement.

Total knee replacement often is performed with tourniquet application. The advantages of a dry field, including fixation, are well known, but it still is debatable if tourniquet application increases deep vein thrombosis. Measurement of coagulation markers is a well accepted method of studying thrombogenesis activation intraoperatively and postoperatively. Twenty patients undergoing total knee replacement with subarachnoid anesthesia were assigned randomly to two groups: either with tourniquet application (Group I) or without tourniquet application (Group II). There were no differences between patients in the two groups in terms of age, gender, diagnosis (all had osteoarthritis), operative time, and total (intraoperative and postoperative) blood loss. Markers for thrombin generation and fibrinolysis were measured. Blood samples were drawn at four times: baseline before the operation; after bone cuts; after cement fixation (Group II) or 2 minutes after tourniquet deflation (Group I); and 1 hour after surgery. Markers of thrombin generation and fibrinolysis showed a significant increase from baseline in all the patients. In Group II these markers started to increase during surgery, whereas in Group I the increase occurred at the end of the procedure when the tourniquet was deflated. The total amount of thrombin generation was significantly higher in Group II (without tourniquet), whereas fibrinolysis was significantly greater in Group I. Total knee replacement is accompanied by a hypercoagulative state with or without the use of a tourniquet, but it seems to be higher when the tourniquet is not used. In addition, tourniquet application may increase fibrinolysis.

Distal femoral varus osteotomy in the valgus osteoarthritic knee.

The results of 18 distal femoral varus osteotomies performed in 18 patients between 1982 and 1993 were evaluated. All patients had degenerative arthritis of the lateral compartment of the knee associated with a valgus deformity. At surgery, the average patient age was 54 years (range: 38-75 years). The average follow-up was 9 years (range: 5-16 years). The average tibiofemoral angle was 17.5 degrees of valgus preoperatively and 6 degrees postoperatively. Seventeen patients (1 patient died from an unrelated cause) were evaluated at follow-up according to the Knee Society rating system. At follow-up, 13 (77%) were rated as good or excellent by the Knee Society rating system. The Knee score improved from 54 points preoperatively to 89 points postoperatively. The functional score improved from 65 points preoperatively to 86 points postoperatively. One knee required a subsequent total knee arthroplasty (TKA) 5 years after osteotomy due to severe and persistent pain. No patient had infection or nonunion. Varus osteotomy of the distal femur is a reliable and effective surgical procedure for the treatment of gonarthrosis associated with valgus deformity in both young and older active patients, where it can be an alternative to TKA.

[Risk factors and prevention of infections of hip and knee prostheses]. / Entità del rischio e prevenzioni delle infezioni nelle protesi d'anca e ginocchio.

Prevention of deep periprosthetic infection requires appreciation of the contributing factors to this phenomenon. The concept of an interdependent relationship between the bacteria, wound and host is most useful when considering the prevention of infections. Establishment of infection depends on the number and virulence of the bacteria, the host's ability to eliminate those bacteria and the status of the wound. Multiple variables contribute to the deposition and proliferation of bacteria into the wound environment which enhance the infectious process, such as the presence of a prosthetic implant or medical conditions and medications which impair the patient's defense. Prevention must address optimization of the wound environment, minimizing the number of bacteria into the wound and augmenting the host defenses. Administration of prophylactic antimicrobials prior to skin incision reduces the incidence of wound infections. The optimal antimicrobial agent should have excellent in vitro activity against staphylococci and streptococci, a long serum half-life, good tissue penetration, be non-toxic and inexpensive.

Femoral tunnel position in anterior cruciate ligament reconstruction using three techniques. A cadaver study.

The possibility of achieving correct deep femoral tunnel positioning during anterior cruciate ligament (ACL) reconstruction with the double incision technique (DI), the transtibial technique (TT), and the anteromedial technique (AM) was evaluated in 30 cadaver knees. A reference hole was made just deep to the insertion of the anteromedial bundle of the ACL through an anteromedial arthrotomy. In the DI technique, a Kirshner wire was inserted outside-in using a rear entry C guide. In the TT and AM techniques, the K-wire was inserted inside-out through the tibial tunnel and through the arthrotomy, respectively. The reference hole could be achieved with each technique. Using lateral radiographs, the superficial aspect of the intra-articular exit of the femoral tunnel was found to be located on average at 36%, 36%, and 34% of the width of the condyles from the posterior margin (NS). None of the holes was more anterior than 40%. In conclusion, a deep femoral tunnel positioning could be achieved with each technique. The choice of technique must be based on the surgeon's preference and clinical results.

The Insall-Burstein total knee replacement in osteoarthritis: a 10-year minimum follow-up.

A total of 99 Insall-Burstein posterior stabilized (IBPS) knee replacements were implanted in 86 osteoarthritic patients. We reviewed 60 knees with a 10- to 15-year follow-up. Using the Knee Society score, 35 knees (58%) were excellent, 15 (25%) good, 4 (7%) fair, and 6 (10%) poor. Flexion at follow-up was 106 degrees on average. Moderate patellofemoral crepitation was present in 5 knees (9%), and 11 knee required excision of a synovial nodule proximal to the patella. Radiographic analysis showed 5 osteolytic lesions (8%) around well-fixed tibial and femoral components and minimal (1 mm) narrowing of the medial polyethylene thickness in 7 knees (12%). There were 6 (10%) failures requiring reoperation because of aseptic loosening (4 knees), deep infection (1 knee), and recurrent patellar dislocation (1 knee). Survivorship analysis using revision as the endpoint showed a cumulative success rate of 92% at 10 years. In this study, the IBPS knee has shown good long-term results with low rates of aseptic loosening and no failures attributable to polyethylene wear.

The relationship between the intercondylar roof and the tibial plateau with the knee in extension: relevance for tibial tunnel placement in anterior cruciate ligament reconstruction.

The relationship between the intercondylar roof and the tibial plateau with the knee in full extension was studied in 100 patients with a unilateral anterior cruciate ligament (ACL) lesion. A lateral view of both knees in full extension with superimposition of the femoral condyles was obtained with the fluoroscope. We found that, in the normal knee, the roof line intersects the tibial plateau (roof-plateau intersection ratio) at 31.5% (SD +/- 5%) of its width and at 33.9% (+/- 5.4%) in the ACL deficient knee (P < .001). The difference was attributable to a subtle anterior tibial displacement in the ACL-deficient knee. Multiple regression analysis showed a direct relationship between roof-plateau intersection ratio and the angle between roof line and tibial plateau (P = .0006). A direct relationship of borderline significance (P = .06) was present with the knee recurvatum measured clinically. In conclusion, the roof-plateau intersection ratio has a wide range of variability (22% to 41%). The larger the roof-plateau angle the more posterior the roof-plateau intersection ratio.

Procedure-dependence and tissue factor-independence of hypercoagulability during orthopaedic surgery.

The increased risk for deep vein thrombosis (DVT) after orthopaedic surgery has been well documented as well as hypercoagulable state during both total hip arthroplasty (THA) and total knee replacement (TKR). To investigate the influence of the surgical procedure [posterolateral (PL) or lateral (L) approach for THA, use of tourniquet (TQ) or not use of TQ for TKR] on the hypercoagulability and the role of extrinsic pathway activation and endothelial stimulation during orthopaedic surgery we have examined 40 patients (20 patients undergoing primary THA--10 with PL approach and 10 with L approach--and 20 patients undergoing TKR--10 with TQ application and 10 without TQ). Thrombin-antithrombin complexes (TAT), tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombomodulin (TM) and von Willebrand factor antigen (vWF:Ag) were analyzed before and during the orthopaedic surgery. During THA, TAT plasma levels increased more markedly in patients assigned to the L than PL approach (p <0.05); during TKR an elevation of TAT of higher degree (p <0.05) was observed when TQ was not applicated. Blood clotting activation was significantly (p <0.001) more relevant during THA than TKR. No changes in TF and vWF:Ag plasma levels were observed in all patients undergoing THA and TKR. TFPI plasma levels significantly (p <0.05) decreased 1 h after the end of the THA in group PL and group L, whereas they remained unaffected in the two groups of patients undergoing TKR. Similarly TM plasma levels significantly decreased during THA, but not during TKR. In conclusion, these results show that: 1) the site of surgical procedures and the type of approach affect the degree of hypercoagulability, 2) the blood clotting activation takes place in the early phases of orthopaedic surgery, without signs of extrinsic pathway and endothelial activation.

Arthroscopic meniscectomy for discoid lateral meniscus in children and adolescents: 10-year follow-up.

Seventeen adolescents underwent arthroscopic lateral meniscectomy for discoid lateral meniscus. The average age at surgery was 13.6 years (range: 5-18 years). The main preoperative symptom was pain in 16 knees and extension loss in 1 knee. At arthroscopy, 10 menisci were complete, 4 were incomplete, and 3 were Wrisberg type. Arthroscopic total meniscectomy was performed in the 3 Wrisberg types, 2 complete types, and 1 incomplete type. The remaining menisci underwent partial meniscectomy. The average follow-up was 10 years (range: 5-15 years). According to the Ikeuchi rating system, 12 knees were rated as excellent (no symptoms and full range of motion), 4 were rated as good (occasional pain), and 1 was rated as fair (patellofemoral pain in an obese patient). Radiographic evaluation showed development of minor osteophytes in the lateral compartment of 8 knees and <50% narrowing of the lateral joint space in 11 knees. No correlation was found between meniscal type, type of meniscectomy (partial or total), and clinical and radiographic results. Arthroscopic lateral meniscectomy for discoid lateral meniscus in adolescents was effective in relieving symptoms during a 10-year follow-up period. Longer follow-up is needed to ascertain the significance of the radiographic changes seen in this study.

Anatomic versus non-anatomic tibial fixation in anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft.

We prospectively compared two series of 30 anterior cruciate ligament (ACL) reconstructions each where the bone-patellar tendon-bone graft was alternately fixed at the level of the tibial plateau (group A; anatomic fixation) or distal to the plateau level (group B; non-anatomic fixation). In group A, a 35-mm-long tibial tuberosity bone block was harvested. The distal 10-15 mm were resected and fixed proximally to the undersurface of the tendon to shorten it. After an average 18 months' follow-up, there were no significant differences between the two groups concerning subjective evaluation, symptoms, range of motion and objective stability. Tibial tuberosity pain was more frequent in group A (53% vs 17%, P = 0.01). Radiographic evaluation showed that tibial tunnel enlargement was less frequent in group A (23% vs 43%, P = 0.02). There was no correlation between tunnel enlargement and objective stability. In conclusion, fixation of the graft at the tibial plateau level did not improve objective stability in this study. Because of the greater technical difficulty and occurrence of tibial tuberosity pain, this technique is not recommended.

Arthroscopic-assisted anterior cruciate ligament reconstruction with the central third patellar tendon. A 5-8-year follow-up.

We reviewed 89 arthroscopically assisted patellar tendon anterior cruciate ligament (ACL) reconstructions for chronic isolated injuries with an average follow-up of 7 years (range 5.4 to 8.6 years). Pain was present in 7 knees (8%). Giving-way symptoms were reported by 7 patients (8%). A KT-2000 side-to-side difference over 5 mm at 30 lbs was recorded in 12 cases (16%). The pivot shift was glide in 17 cases (19%) and clunk in 10 (11%). A 3 degrees-5 degrees extension loss compared with the normal side was present in 20 knees (22%) and 6 degrees-10 degrees in 4 knees (4%). The intra-articular exit of the femoral tunnel was misplaced in the anterior 50% of the condyles along the roof of the notch in 10% of the knees. This positioning significantly (P = 0.003) increased the frequency of graft failure (62.5%) compared with the cases with a more posterior placement (graft failure 12%). An anterior position of the intra-articular exit of the tibial tunnel (in the anterior 15% of the sagittal width of the tibia) significantly (P = 0.01) increased the frequency of extension loss > 5 degrees. Medial meniscectomy was associated with a 35% incidence of narrowing of the medial joint space, which was significantly higher compared with knees with normal menisci (9%; P = 0.04) or with medial meniscal repair (7%; P = 0.05). In conclusion this study showed satisfactory anterior stability (KT-2000 side-to-side difference up to 5 mm and pivot absent or glide) in 83% of the knees. This percentage increases to 88% in the knees with a correct posterior and proximal femoral tunnel placement. Accuracy in tunnel positioning is essential for the success of ACL surgery. Meniscal repair was effective in decreasing joint space narrowing and should be attempted when possible.