Lateral Parapatellar Approach Research Articles

A Case of Simultaneous Total Knee Arthroplasty in Congenital Dislocation of the Patella

The gonarthrosis with congenital dislocation of the patella is rare condition. This paper will report about total knee arthroplasty (TKA) for the valgus knee with bilateral congenital dislocation of the patella. A 52-year-old woman presented to our hospital with progressive pain in bilateral knees. Both knee showed severe valgus deformity and lateral dislocation of the patella. Anteroposterior weight-bearing radiographs showed osteoarthritic changes in the lateral compartment with 7 valgus deformity at the right and 15 at the left. A bilateral TKA with cruciate retained components (NAKASHIMA FINE) was performed. Good tracking of the patella was achieved by using a lateral parapatellar approach and vastus medialis plication. There are no normative guidelines of operative procedure about TKA for osteoarthritis of valgus knee with congenital dislocation of the patella. With some referencing to current literature, strategies to good patella tracking are discussed.

Clinical Outcomes and Survivorship of Lateral Unicompartmental Knee Arthroplasty: Does Surgical Approach Matter?

BackgroundLateral unicompartmental knee arthroplasty (UKA) has been shown to be an effective procedure to treat isolated lateral compartment osteoarthritis with excellent long-term survivorship. Whether a medial parapatellar approach or a lateral parapatellar approach is superior in lateral UKA is unknown. The purpose of this study was to determine if there is a difference in intermediate-term clinical outcomes in patients undergoing lateral UKA through a lateral vs medial parapatellar approach. MethodsWe retrospectively reviewed a consecutive series of 65 patients who underwent lateral UKA with a minimum of 2-year follow-up. Fifty-two patients (80%) had a lateral approach and 13 (20%) a medial parapatellar approach. Patient demographics, preoperative and postoperative radiographic findings, need for revision surgery, Knee Society Score, and range of motion were assessed. ResultsOverall survivorship was 94% at a mean of 82 months; with the sample size available for study, there was no difference in survivorship between the groups. There was no difference in Knee Society Score or revision to total knee arthroplasty (5% vs 7%, P = 1.000) between the medial and lateral approach groups. Comparatively, the lateral approach group did have significantly greater postoperative flexion (123.6° vs 116.5°, P = .006) and greater improvement in flexion from preoperative measurements (3.0 vs −8.0°, P = .010). ConclusionAlthough our sample size was small, we could not demonstrate a difference in revision rates or clinical outcome scores when comparing a lateral or a medial approach with lateral UKA at intermediate-term follow-up. A lateral approach did have greater postoperative flexion, but its clinical significance remains undetermined.

Lateral parapatellar and subvastus approaches are superior to the medial parapatellar approach in terms of soft tissue perfusion.

The arthrotomy techniques of knee surgery may cause varying degrees of disruption to the tissue blood supply. The aim of this study was to investigate the effects of the medial parapatellar (MPPa), midvastus (MVa), subvastus (SVa) and lateral parapatellar (LPPa) approaches on regional tissue perfusion of the knee. In this experimental study, a total of 28 female rabbits were applied with four different arthrotomy techniques as Group MPPa, Group MVa, Group SVa and Group LPPa. The blood supply of the tissue around the knee was examined by scintigraphic imaging including the perfusion reserve and T max, and biochemical alteration of the oxidative stress parameters including malondialdehyde (MDA), fluorescent oxidation products (FlOPs), and histopathological findings were evaluated on tissue samples after 3weeks. The perfusion reserve was increased in all four groups compared to the healthy, contralateral knees. In the Group LPPa, the vascularity was significantly increased compared to the Group MPPa (p=0.006). In the examination of biochemical parameters, the increase in MDA levels was statistically significant in the Group MPPa compared with the Group LPPa (p=0.004), and in the Group MVa compared with the Group LPPa (p=0.006). The increase in the value of MDA levels was striking in the Group MPPa and Group MVa compared with the control group (p=0.004, p=0.004, respectively). The increase in another oxidative stress parameter, the tissue FlOPs levels, was statistically significant in the Group MPPa compared with the control group (p=0.035). The LPPa and SVa caused less oxidative stress and less disruption of the muscle blood supply, in biochemical and scintigraphic parameters, compared to the MPPa and MVa. Therefore, in clinical practice, the SVa is preferable to the MPPa and MVa in total knee arthroplasty and the LPPa should be preferred more frequently in selected cases with critical soft tissue viability.

Medial parapatellar approach leads to internal rotation of tibial component in total knee arthroplasty.

The purpose of this study was to investigate if the type of approach [medial parapatellar approach (MPA) versus lateral parapatellar approach with tibial tubercle osteotomy (LPA)] influences rotation of femoral and/or tibial component and leg axis in total knee arthroplasty (TKA). It was the hypothesis that MPA leads to an internally rotated tibial TKA component. This study included 200 consecutive patients in whom TKA was performed using either a parapatellar medial (n=162, MPA) or parapatellar lateral approach with tibial tubercle osteotomy (n=38, LPA). All patients underwent clinical follow-up, standardized radiographs and computed radiography (CT). TKA components' position and the whole leg axis were assessed on 3D reconstructed CT scans (sagittal, coronal and rotational). Mean values of TKA component position and the whole leg alignment of both groups were compared using a t test. The tibial component was graded as internally rotated (<3° of external rotation (ER)), neutral rotation (equal or between 3° and 6° of ER) and externally rotated (>6° ER). The femoral component was graded as internally rotated [>3° of internal rotation (IR)], neutral rotation (equal or between -3° IR and 3° of ER) and externally rotated (>3° ER). There was no significant difference in terms of whole leg axis after TKA between both groups (MPA: 0.2° valgus±3.4; LPA: 0.0° valgus±3.5). Means of tibial component rotation were 2.7° ER±6.1 (MPA) and 7.6° ER±5.4 (LPA). Patients of group LPA presented a significantly less internally rotated (LPA: 18.4%; MPA: 48.8%) and more externally rotated (LPA: 52.6%; MPA: 22.8%) tibial component (p<0.001). No significant differences were seen for the femoral component position, tibial valgus/varus and tibial slope. The type of approach (medial versus lateral) significantly influenced tibial TKA component rotation. It appears that a MPA tends to internally rotate the tibial TKA component and a LPA tends to externally rotate the tibial TKA. The anterior cortex should not be used as landmark for tibial TKA component placement when using the lateral approach with tibial tubercle osteotomy. Retrospective comparative study, Level III.

Research progress of Hoffa fracture

Hoffa fracture is a rare type of fracture confined to the coronal plane of the femoral condyle. High-energy is a common reason of Hoffa fracture, and low-energy trauma and iatrogenic injury can also cause Hoffa fracture in some cases. The commonly used classifications include Letenneur classification, CT classification, AO classification and modified AO classification. X-ray is the first choice to diagnose Hoffa fractures, fracture lines can be found. If the X-ray is negative, CT scan and MRI should be performed. Nondisplaced fractures can be managed conservatively with cast immobilization, however, there is high risk of redisplacement. Open reduction and internal fixation is preferred. For the young patient with good compliance, a simple medial or lateral condylar fractures can be treated via medial or lateral parapatellar approach. When the fracture is exposed, the headless compression screws can be inserted vertical to the fracture line from backward to forward. For a bicondylar fracture, median parapatellar incision can be selected. While for a complex fracture with osteoporosis or high body mass index, cannulated screws with anti-sliding plate fixation technique should be used.

Surgical approaches to intramedullary nailing of the tibia: Comparative analysis of knee pain and functional outcomes

IntroductionPost-operative knee pain is common following intramedullary nailing of the tibia, regardless of surgical approach, though the exact source is controversial. Historically, the most common surgical approaches position the knee in hyperflexion, including patellar tendon splitting (PTS) and medial parapatellar (MPP). A novel technique, the semi-extended lateral parapatellar approach simplifies patient positioning, fracture reduction, fluoroscopic assessment, and implant insertion. It also avoids violation of the knee joint capsule. However, this approach has not yet been directly compared against the historical standards. We hypothesised that in a comparison of patient outcomes, the semi-extended approach would be associated with decreased knee pain and better function relative to knee hyperflexion approaches. MethodsA trauma patient database from a Level I centre was queried for patients who underwent intramedullary nailing of the tibia between 2009 and 2013. Patients were surveyed for knee pain severity (NRS scale 1 to 10) and location, and completion of the Lysholm Knee Scale (LKS). Data was compared between the semi-extended lateral parapatellar, medial parapatellar, and tendon splitting groups regarding knee pain severity, location, total LKS, and individual knee function scores from the Lysholm questionnaire. Pre-hoc power analysis determined the necessary sample size (n=34). Post-hoc analysis utilised two-way ANOVA analysis with a significance threshold of p<0.05. ResultsComparison of knee pain severity between the groups found no significant difference (p=0.69), with average ratings of: semi-extended (3.26), PTS (3.59), and MPP (3.63). Analysis found no significant differences in total LKS score (p=0.33), with average sums of: semi-extended (75.97), MPP (77.53), and PTS (81.68). Individual knee function scores from the LKS were similar between the groups, except for limping, with MPP being significantly worse (p=0.04). There was no significant difference in knee pain location (p=0.45). ConclusionIn this adequately-powered study, at minimum 1 year follow-up there were no significant differences between the 3 approaches in knee pain severity, location, or overall function. The three were significantly different in post-operative limping, with medial parapatellar having the lowest score. The semi-extended lateral parapatellar approach vastly simplifies many technical aspects of nailing compared to knee hyperflexion approaches, and does not violate the knee joint.

Proximal Tibia Chondroblastoma Treated With Curettage and Bone Graft and Cement Use.

Chondroblastoma has a predilection for the epiphyses or apophyses of long tubular bones. Management of lesions in the proximal tibia is challenging because it is difficult to gain access to intraepiphyseal lesions for completion of curettage. From October 2007 to December 2011, 9 patients with de novo chondroblastoma of the proximal tibia underwent surgery at the authors' institution. All patients initially presented with pain, and 5 patients had limitation of range of motion of the ipsilateral knee. Four lesions abutted the tibial attachment sites of the cruciate ligaments. Surgical procedures included intralesional tumor curettage, additional burring, and packing of the defect with bone graft and/or bone cement. The extra-articular approach was used according to tumor location. The medial or lateral parapatellar approach was used when the tumor was located in the anterior two-thirds of the horizontal plane. When a lesion was located in the posterior third, the posteromedial or posterolateral approach was used as the lesion was cornered. Mean duration of follow-up was 47.2 months (range, 27-80 months). No local recurrence or pulmonary metastasis was noted at latest follow-up. Mean functional score was 29.3 points (range, 28-30 points). All patients fully recovered range of motion in the affected knee. No avulsion fracture or anteroposterior instability of the knee joint was detected. Results of the current study suggest that intralesion curettage followed by additional burring with an extra-articular approach is a successful treatment option for chondroblastoma of the proximal tibia.

The Lateral Parapatellar Approach With Computer Navigation for Uncorrectable Valgus Knees Requiring Arthroplasty

The uncorrectable valgus knee provides an increased challenge for total knee arthroplasty due to the decreased lateral femoral bone stock, tight lateral soft tissues, and lax medial structures. The less utilized lateral parapatellar (LPP) approach potentially has advantages over the medial approach

Equivalent results of medial and lateral parapatellar approach for total knee arthroplasty in mild valgus deformities.

When performing total knee arthroplasty (TKA) in valgus knee deformities, a medial or lateral parapatellar approach can be performed, but the lateral approach is often considered technically more difficult. The purpose of this study was to compare intra-operative, early clinical and radiological outcomes of medial and lateral parapatellar approaches for TKA in the setting of moderate knee valgus (<10°). We prospectively analysed 424 knees with pre-operative valgus deformity between 3° and 10° that underwent TKA over an 18-year period; 109 were treated with a medial approach and 315 with a lateral approach. Intra- and post-operative outcomes and complication rates after a minimum follow-up of one year were compared. Tourniquet (p = 0.25) and surgical (p = 0.62) time were similar between groups. The popliteus tendon was released more frequently in the medial-approach group (p = 0.04), while the iliotibial band was released more frequently in the lateral-approach group (p < 0.001). A tibial tuberosity osteotomy was performed more frequently in the lateral- than medial-approach group (p = 0.003). No significant differences in limb alignment (p = 0.78), or Knee Society Score (KSS) knee (p = 0.32) and function (p = 0.47) results were noted based on surgical approach, and complication rates were similar between groups (p = 0.53). Lateral parapatellar approach is a safe and effective surgical technique for performing TKA in moderately valgus knees. These equivalent early results are encouraging for systematic use of the lateral approach in moderately valgus knees.

Il trattamento con placche e viti delle fratture del terzo distale di femore

Distal femur fractures can result from high-energy trauma in men under 30 years of age or from low-energy trauma in women over 75. Surgical fixation of distal femoral fractures has evolved to the point that non-operative treatment entails a higher risk of complications, which makes surgical intervention the treatment of choice in most of these fractures. The lateral approach to the distal femur allows for visualization, reduction and fixation of simple articular fractures. More complex fractures are better exposed with a lateral parapatellar approach (Krettek’s approach). Plate osteosynthesis is indicated in fractures of the distal femur Type 33-A, in particular in high comminution subgroups, and in case of Type 33-C according to the AO classification system. Evolving materials and design have enhanced plates reliability. Nevertheless, the surgical technique is extremely demanding, and even a mild inaccuracy may lead to an high rate of complications, down to complete synthesis failure. If articular involvement is identified at imaging, adequate surgical exposure and accurate reconstruction of the articular surface must be performed. Mininvasive techniques with biological saving of periosteal vascularization and lower soft tissue damage may promote bone consolidation and must be considered by the surgeon.

Arthroplasty in the Valgus Knee: Comparison and Discussion of Lateral vs Medial Parapatellar Approaches and Implant Selection.

Constrained implants are frequently used for primary total knee arthroplasty (TKA) in patients with moderate and severe genu-valgum (>10˚). This deformity presents corrective challenges for ligament release. The lateral-parapatellar approach has been advocated as an alternative to the traditional medial-parapatellar approach. Claimed advantages include better access for release of tight ligamentous structures, without requirement for release of the medial-collateral ligament.We present our comparative experience of the use of an unconstrained knee-replacement prosthesis inserted by the lateral-parapatellar approach in comparison to a constrained-knee prosthesis inserted via the medial-parapatellar approach.49 primary total knee-replacements in 48 (6 males, 42 females) patients were performed; 32 through a lateral-parapatellar approach (group L) using an unconstrained-prosthesis and 17 through a medial-parapatellar approach more often requiring a constrained-prosthesis (group M). Mean preoperative valgus angle was 18.5 (range 11-34˚). Patient demographics (p=0.7) and valgus correctability were similar between the two groups.There was no significant difference in the mean post-operative valgus angle. This was 4.2˚ (range 1-9.5˚) using the lateral-parapatellar approach and 5.3˚ (range 0.3-10˚), p=0.12, using the medial-parapatellar approach.Transient common peroneal injury occurred in 2 patients, both group L, in the presence of valgus angles of greater than 20˚. To date no joints have been revised, or are unstable.The use of a lateral-parapatellar approach, appropriate soft tissue release, and an unconstrained PCL-preserving implant, yielded in all cases a stable, well aligned knee arthroplasty. This represents a viable alternative to the constrained-prosthesis using a medial-parapatellar approach in patients with moderate and severe genu-valgum.

Radiological assessment of the safe zone for medial minimally invasive plate osteosynthesis in the distal femur with computed tomography angiography

IntroductionSurgical treatment options for distal femur fractures include intramedullary nailing or plating using a lateral or lateral parapatellar approach. However, medial plating is required for additional stability in some fractures such as severely comminuted fractures and periprosthetic fractures, and in those for which use of a lateral plate or nail is not appropriate. This study aimed to explore the safe zone for medial minimally invasive plate osteosynthesis of the distal femur with computed tomography angiography. Material and methodsIn a series of 30 patients, the region of interest between the lesser trochanter (LT) to the adductor tubercle (AT) was divided into six levels (I to VI), and the distance from the femur to the femoral artery (FA) was measured. At each level, the medial half of the femur was divided into eight sections that were assigned ‘A to H’ from anteromedial to posteromedial, and the position of the FA and the deep femoral artery (DFA) was recorded. ResultsThe average length from the LT to AT was 295.0mm. The average distance to FA was 38.0mm, 29.9mm, 26.9mm, 27.0mm, 21.8mm, and 12.2mm from level I to VI, respectively. The FA was positioned posteromedially below level IV and positioned at C–H below level II, which was out of the anterior aspect of the femur. The DFA was in the same location as the FA between levels II and III. ConclusionThe anteromedial aspect of the distal half of the femur is the safe zone, and a long plate can be positioned safely in this zone at the anterior aspect up to the level of 8cm below the LT.

Lateral Parapatellar Approach Without Tibial Tubercle Osteotomy for Fixed Valgus Deformity Correction in Total Knee Arthroplasty.

The lateral parapatellar approach provides direct access to the pathological area in a valgus knee deformity and allows sequential titrated release of contracted lateral soft tissues during total knee arthroplasty. Differentiate the flexible and fixed components of the valgus deformity by clinical and radiographic examination. Open the knee joint from the lateral side by coronal z-plasty of the lateral retinaculum, oblique lateral tenotomy of the quadriceps tendon, and iliotibial band release. Perform a quadriceps snip and expose the knee joint. Make proximal tibial and distal femoral cuts in appropriate alignment. A rectangular extension gap is the goal. Determine the femoral component size and femoral rotation, and balance the flexion gap. Confirm tibial rotational alignment, fix the components, and assess patellar tracking. Perform closure of the prosthetic joint with expanded lateral structures. Between 2003 and 2009, thirty-two knees with clinical valgus deformity of >10° underwent total knee arthroplasty with an expansile lateral arthrotomy technique11.IndicationsContraindicationsPitfalls & Challenges.

Lateral parapatellar approach with tibial tubercle osteotomy for the treatment of non-correctable valgus knee osteoarthritis: A retrospective clinical study

BackgroundThe aim of this retrospective study was to evaluate the efficacy of a lateral parapatellar approach combined with a tibial tubercle osteotomy (TTO) in patients undergoing total knee arthroplasty (TKA) with non-correctable valgus knee osteoarthritis. MethodsWe studied 53 consecutive patients (57 knees) who had a primary TKA via lateral parapatellar approach with a global step-cut “coffin” type TTO over a 10-year period. All patients had non-correctable grade II valgus deformity according to the Ranawat classification. The average age of patients was 71years (45 to 77) and the mean follow-up was 39months (20 to 98). ResultsPost-surgery, there was a significant improvement in knee extension (p=0.002), flexion (p=0.006), Knee Society Pain and Function Scores (p<0.001) and WOMAC Osteoarthritis Index (p<0.001). The tibiofemoral angle changed from a preoperative median value of 11deg (10 to 17) to a postoperative value of 3.75deg (0 to 9). Congruent patellar tracking was observed in all cases. All but one osteotomy united in a median period of 16.7weeks (9 to 28) and no hardware removal was required. One knee developed infection treated with two-stage reconstruction. A proximal tibial stress fracture also occurred in a patient on long-term bisphosphonate therapy. ConclusionLateral parapatellar approach along with TTO is an effective technique for addressing non-correctable valgus knee deformity during TKA.

Efficacy and Mid Term Results of Lateral Parapatellar Approach Without Tibial Tubercle Osteotomy for Primary Total Knee Arthroplasty in Fixed Valgus Knees

The lateral parapatellar approach, despite providing direct access to the pathological area has not been widely accepted for knee arthroplasty in valgus deformities. We performed a modified lateral (Keblish) approach which consisted of coronal z plasty of lateral retinaculum, quadriceps snip, titrated sequential lateral release and closure with expanded lateral structures in 32 arthritic fixed valgus knees. In 30 knees, either tendon of popliteus or lateral collateral ligament or both could be preserved. At an average follow-up of 5 years, the valgus alignment improved from 25.4° (11°-60°) to 4° (0°-10°) and knee society score improved from 34 to 95 points. There was no late instability or revisions. This approach is rational, eliminates patella maltracking, is applicable in severe deformities and with titrated release, can preserve the posterolateral knee stabilizers that are necessary for long term implant survival.

One-year Postoperative Knee Pain in Patients With Semi-extended Tibial Nailing Versus Control Group

The purpose of this study was to determine whether patients with a tibia fracture who were treated with an intramedullary nail using a semi-extended, extra-articular, parapatellar approach had anterior knee pain at a higher than acceptable incidence compared with control patients. Eighteen patients with OTA type 42 A-C tibia fractures nailed using this approach were compared with an uninjured control group (n = 22). Lysholm Knee Score questionnaires were given to all participants and compared between groups. Fracture patients completed the LKS at 6 months and 1 year postoperatively. Additional data collected included age, sex, mechanism of injury, OTA classification, Gustilo/Anderson and Tscherne classification, nail-apex distance, complications, weight-bearing status, additional fixation needed, and postoperative procedures. Mean age and demographics were similar between the fracture and control group: 42.9 vs 47.9 years, respectively, (P=.36) and 11 vs 9 men, respectively (P=.11). Lysholm Knee Scores among the subgroups (age, sex, medial vs lateral parapatellar approach, soft-tissue status, and nail-apex distance) showed no statistically significant differences (P>05 for all comparisons). Mean nail-apex distance was -16.3 mm. Mean LKS score 1-year postoperatively was 87.3 (range, 59-100) in the fracture group and 89.7 (range, 23-100) in the control group (P=.69). At 1-year postoperatively, patients in the fracture group did not have increased anterior knee pain compared with the control group.

Die sagittale Gleitosteotomie des lateralen Kondylus nach Briard beim Oberflächenersatz des kontrakten Valgusknies

Distalization of the insertion of the lateral collateral ligament and popliteus tendon by sliding osteotomy of the lateral femur condyle in order to correct a residual contracture in extension in total knee arthroplasty (TKA) of the severe valgus deformity. Genuine and other valgus deformity of the knee. Severe laxity of the medial collateral ligament; common contraindications of joint replacement. Lateral parapatellar approach and stepwise osteotomy of the tubercle of the tibia, subperiostal release of the lateral contracted structures such as iliotibial band (ITB) and lateral collateral ligament (LCL) in flexion. Tibia first technique, verification of a balanced and stable flexion gap parallel to the epicondylar line. Posterior cruciate ligament (PCL) is preserved. Referencing of the distal femoral cut by a spacer filled only in the medial extension gap. Finishing femoral chamfer cuts. If extension gap remains trapezoidal, further release of the residual lateral contracted structures in extension by means of sliding osteotomy of the lateral condyle and subperiostal release of the capsule and the lateral septum intermusculare is required. Termporary fixation of the lateral condyle by K-wires, resection of the bony excess, trial of test components, definite screw fixation. Comparable to TKA in varus deformities by a medioparapatellar approach. A total of 79patients (61 women, 18 men, average age 71years at the time of surgery) with fixed valgus deformities were operated between June 2001 and December2010 using TKA and sliding osteotomy of the lateral femoral condyle. The preoperative valgus angle under defined valgus and varus stress was 19.5° (8-40), postoperative 4.7° (2-11). Mean medial angle (valgus stress) of the follow-up was 2.1° (0.5-5°), lateral angle (varus stress) 2.3° (0.5-5°). A total of 35patients were followed-up, at a mean of 73.3month (24-109months). The postoperative Knee Society Score was 95 points (56-100points), while the postoperative Function Score was 90 points (55-100points) postoperatively. The Oxford Score improved from 22points (3-43points) preoperatively to 45 points (21-48points) postoperatively. One knee had to be revised due to infection, one knee due to non-union of the tibial tubercle. Finally, there were 3cases with complications associated with the procedure due to the sliding osteotomy of the lateral femoral condyle; all were revised successfully. No conversion to a semi-constrained or constrained knee prosthesis was necessary.

Tuberositasosteotomie in der Knieendoprothetik

Tibial tubercle osteotomy facilitates access to the knee joint without excessive tension of the extensor apparatus with the lateral parapatellar approach and the medial parapatellar approach in case of contracture or revision arthroplasty. Inadequate exposure of the knee joint with the lateral parapatellar approach and inadequate exposure of the knee joint with the medial parapatellar approach in case of contracture and revision arthroplasty. Severe periarticular osteoporosis or bone atrophy after knee arthroplasty and damage to the patella tendon insertion due to previous operations. A bone block 8-10cm long is excised with the tibial tubercle using an oscillating saw. A step cut inferior to the tibial plateau is created with a chisel. Refixation is performed with two cortical screws. Alternatively, in case of poor bone quality, refixation is accomplished with two cerclage wires. In case of stable refixation, full weight bearing is allowed with an extension brace for 2-4weeks and passive flexion is increased as tolerated. In case of poor bone quality, it is recommended that full weight bearing be postponed for 6weeks, whereby full flexion is regained in 30° steps at 2, 4, and 6weeks postoperatively. From 2001-2004, 67 osteotomies of the tibial tubercle were performed for revision arthroplasty. During follow-up in 2010, no pseudarthrosis or dislocation was noticed. Postoperatively, two hematoma and one skin necrosis had to be revised. The risk of hematoma and pseudarthrosis or dislocation of the fragment can be minimized by using the correct operative technique.

Lateral Unicompartmental Knee Arthroplasty Through a Lateral Parapatellar Approach Has High Early Survivorship

The literature suggests lateral unicompartmental knee arthroplasties are associated with low revision rates. However, there are fewer reports describing techniques for lateral unicompartmental arthroplasty and whether technique influences ROM and function compared to reports for medial unicompartmental arthroplasty. We report our indications for lateral unicompartmental arthroplasty, how we perform this procedure, and the subsequent Knee Society scores, ROM, and revision and reoperation rates. From a retrospective review of electronic records from 2004 through 2008, we identified 93 patients who had 100 lateral unicompartmental arthroplasties. Indications were complete lateral bone-on-bone arthrosis with a correctible deformity and maintenance of the medial joint space on varus stress radiographs or isolated lateral disease by diagnostic arthroscopy. Average age was 68 years. Seventy percent of patients were women. At followup, we obtained Knee Society scores and ROM. Minimum followup was 24 months (average, 39 months; range, 24-81 months). At followup, Knee Society scores averaged 46 for pain, 94 for clinical, and 89 for function, and ROM averaged 124°. Three patients had reoperations: one an open reduction and internal fixation for fracture at 2 years postoperatively, one an arthroscopy for a medial meniscal tear, and one a revision for pain. Based on our observations, we believe complete cartilage loss laterally and correctible deformity with maintenance of the medial joint on varus stress radiographs are reasonable indications for lateral unicompartmental arthroplasty. We recommend a lateral parapatellar approach can be utilized. The early reoperation and revision rates were low.

Total knee arthroplasty in severe valgus knee deformity: comparison of a standard medial parapatellar approach combined with tibial tubercle osteotomy

Primary TKA in valgus knees with a deformity of more than ten degrees may prove challenging, since bone and soft tissue abnormalities make accurate axis restoration, component orientation and joint stability attainment a difficult task. The purpose of this study was to determine which approach is optimal in these patients, by comparing the standard medial parapatellar approach to a lateral parapatellar combined with a tibial tubercle osteotomy (TTO). Forty-four valgus knees--with an axis deviation ranging from 15 to 36 degrees (mean 24°)--were dealt with primary TKA and followed up for a minimum period of 7 years. Lateral parapatellar arthrotomy combined with TTO was performed in 22 individuals (Group A) and a standard medial parapatellar capsulotomy in the remaining patients (Group B). The International Knee Society System Score (IKSS) was used for clinical evaluation. Radiological assessment was performed yearly postoperatively using long films for assessment of the anatomical axis. The postoperative IKSS scores showed no significant statistical difference between groups A and B (P < 0.05). In the alignment parameter, however, residual valgus deviation occurred in 9% of patients from Group A and in 32% from Group B. No late-onset instability was displayed. Lateral parapatellar approach combined with TTO may prove highly beneficial in significant valgus deformities, as the anatomical axis is restored accurately and soft tissue release of the lateral contracted structures facilitated to an important extent.