Delayed detection of clinically significant posterior cruciate ligament injury after peri-articular fracture around the knee of 448 patients

Background

The purpose of this study was to report the frequency with which posterior cruciate ligament (PCL) injuries occurred in combination with peri-articular fractures around the knee, and to determine the frequency with which the detection of these PCL injuries was delayed (i.e., detected in an outpatient clinic after fracture treatment).

Methods

This retrospective study included 448 subjects with peri-articular fractures around the knee, including femoral shaft fractures, distal femoral fractures, patellar fractures, tibial plateau fractures, and tibial shaft fractures. The PCL injuries were detected through clinical examination, magnetic resonance imaging, and stress X-rays. We determined both the frequency of PCL injuries that occurred in combination with peri-articular fractures around the knee, and the frequency with which the detection of these PCL injuries was delayed. We also compared the frequency with which PCL injuries were associated with either isolated or combined fractures for different fracture types.

Results

We identified concomitant PCL injury and peri-articular fracture of the knee in 7.8?% of patients. In 22 of the 35 patients with concomitant PCL injury, the detection of the PCL injury was delayed. There were significant differences in the frequency with which PCL injuries were associated with isolated or combined fractures of the femoral shaft (P?=?0.04), patella (P?=?0.03), and distal femur (P?=?0.03).

Conclusion

The delayed detection frequency was high for PCL injury after peri-articular fracture around the knee.     

Does an Unloader Brace Reduce Knee Loading in Normally Aligned Knees?

Background

Unloading knee braces often are used after tibiofemoral articular cartilage repair. However, the experimental basis for their use in patients with normal tibiofemoral alignment such as those undergoing cartilage repair is lacking.

Questions/purposes

The purpose of this study was to investigate the effect of varus and valgus adjustments to one commercially available unloader knee brace on tibiofemoral joint loading and knee muscle activation in populations with normal knee alignment.

Methods

The gait of 20 healthy participants (mean age 28.3 years; body mass index 22.9 kg/m²) was analyzed with varus and valgus knee brace conditions and without a brace. Spatiotemporal variables were calculated as were knee adduction moments and muscle activation during stance. A directed cocontraction ratio was also calculated to investigate the relative change in the activation of muscles with medial (versus lateral) moment arms about the knee. Group differences were investigated using analysis of variance. The numbers available would have provided 85% power to detect a 0.05 increase or decrease in the knee adduction moment (Nm/kg*m) in the braced condition compared with the no brace condition.

Results

With the numbers available, there were no differences between the braced and nonbraced conditions in kinetic or muscle activity parameters. Both varus (directed cocontraction ratio 0.29, SD 0.21, effect size 0.95, p = 0.315) and valgus (directed cocontraction ratio 0.28, SD 0.24, effect size 0.93, p = 0.315) bracing conditions increased the relative activation of muscles with lateral moment arms compared with no brace (directed cocontraction ratio 0.49, SD 0.21).

Conclusions

Results revealed inconsistencies in knee kinetics and muscle activation strategies after varus and valgus bracing conditions. Although in this pilot study the results were not statistically significant, the magnitudes of the observed effect sizes were moderate to large and represent suitable pilot data for future work. Varus bracing increased knee adduction moments as expected; however, they produced a more laterally directed muscular activation profile. Valgus bracing produced a more laterally directed muscular activation profile; however, it increased knee adduction moments.

Clinical Relevance

When evaluating changes in knee kinetics and muscle activation together, this study demonstrated conflicting outcomes and questions the efficacy for the use of unloader bracing for people with normally aligned knees such as those after articular cartilage repair.     

Medial Injury in Knee Dislocations: What Are the Common Injury Patterns and Surgical Outcomes?

Background

When associated with a knee dislocation, management of the medial ligamentous injury is challenging, with little literature available to guide treatment.

Questions/purposes

We (1) compared MRI findings of medial ligament injuries between Schenck KDIIIM and KDIV injuries, (2) compared clinical outcomes and health-related quality of life as determined by Lysholm and Veterans Rand 36-Item Health Survey (VR-36) scores, respectively, of reconstructed KDIIIM and KDIV injured knees, and (3) determined reoperation rates of reconstructed KDIIIM and KDIV injured knees.

Methods

Over a 12-year period, we treated 65 patients with knee dislocations involving bicruciate ligament injury and concomitant medial ligament injuries, without or with posterolateral corner injuries (Schenck KDIIIM and KDIV, respectively); 57% were available for followup at a mean of 6.2 years (range, 1.1–11.6 years). These patients were contacted, and prospectively measured clinical outcomes scores (Lysholm and VR-36) were obtained and compared between subsets of patients. Preoperative MRIs (available for review on 49% of the patients) were rereviewed to characterize the medial ligament injuries.

Results

KDIIIM injuries more frequently had complete deep medial collateral ligament tears and posterior oblique ligament tears compared to KDIV injuries. KDIIIM knees had better Lysholm scores (88 versus 67, p = 0.027) and VR-36 scores (88 versus 70, p = 0.022) than KDIV knees. Female sex (Lysholm: 55 versus 85, p = 0.005; VR-36: 59 versus 85, p = 0.003) and an ultra-low-velocity mechanism (injury that occurs during activity of daily living in obese patients) (Lysholm: 55 versus 80–89, p = 0.002–0.013; VR-36: 60 versus 79–88, p = 0.001–0.017) were associated with worse outcomes. The overall reoperation rate was 28%, and the most common indication for reoperation was stiffness.

Conclusions

Medial ligament injury is common in knee dislocations. Females who sustain these injuries and patients who have an ultra-low-velocity mechanism should be counseled at the time of injury about the likelihood of inferior outcomes. As ROM deficits are the most commonly encountered complication, postoperative rehabilitation should focus on early ROM exercises as stability and wound healing allow. Future prospective studies are needed to definitively determine whether operative or nonoperative management is appropriate for particular medial ligamentous injury patterns.     

Femoral Lateral Bowing and Varus Condylar Orientation Are Prevalent and Affect Axial Alignment of TKA in Koreans

Background

Coronal alignment is considered key to the function and longevity of a TKA. However, most studies do not consider femoral and tibial anatomical features such as lateral femoral bowing and the effects of these features and subsequent alignment on function after TKA are unclear.

Questions/purposes

We therefore determined (1) the prevalence of lateral femoral bowing, varus femoral condylar orientation, and severe tibia plateau inclination in female Koreans undergoing TKA; (2) whether postoperative alignments are affected by these anatomical features and improved by the use of navigation; and (3) whether postoperative coronal alignments are associated with function.

Methods

We measured alignment in 367 knees that underwent TKA and 60 sex- and age-matched normal knees (control group). We determined patterns and degrees of femoral bowing angle, femoral condylar orientation, and tibial plateau inclination on preoperative full-limb radiographs. Postoperatively, coronal alignment of limbs and of femoral and tibial components was measured. We compared American Knee Society scores, WOMAC scores, and SF-36 scores in aligned knees and outliers (beyond ± 3° or ± 2°) at 1 year.

Results

The prevalence of lateral femoral bowing was 88% in the TKA group and 77% in the control group. Mean femoral condylar orientation angle was varus 2.6° in the TKA group and valgus 1.1° in the control group, and mean tibial plateau inclination was varus 8.3° in the TKA group and varus 5.4° in the control group. Femoral lateral bowing and varus femoral condylar orientation were associated with postoperative alignments. Several clinical outcome scales were inferior in the outliers in mechanical tibiofemoral angle, anatomical tibiofemoral angle, and tibial coronal alignment but not in femoral coronal alignment outliers.

Conclusions

Lateral femoral bowing, varus condylar orientation, and severe varus inclination of the tibia plateau should be considered when performing TKA in Korean patients or patients with otherwise similar anatomical features.     

Complications after arthroscopic knee surgery

Purpose

To examine the complications of arthroscopic knee surgeries conducted in the Sports Medicine and Knee Center of our hospital.

Subjects and methods

In this prospective study, a total of 2,623 patients (1,396 men and 1,227 women) who underwent arthroscopic knee surgeries in our center between January 2006 and March 2013 (7 years and 3 months) were studied. The ages at surgery ranged 7–96 years (mean 33.5 years). Arthroscopy was conducted because of sports injuries in 1,653 patients (63.0 %). The main diagnoses included meniscal injury in 920 patients, discoid meniscus in 64 patients, anterior cruciate ligament injury in 580 knees, posterior cruciate ligament injury in 30 knees, loose body in 61 knees, and intraarticular fracture in 33 knees. Arthroscopic procedures included meniscectomy in 987 knees, meniscal suture repair in 262 knees, and anterior cruciate ligament reconstruction in 508 knees. Intraoperative and postoperative complications in these cases were investigated.

Results

The rate of complication was 7 in 2,623 cases (0.27 %). Intraoperative complications comprised three cases of intraarticular instrument breakage and one case of meniscal injury. Postoperative complications consisted of two cases of septic arthritis and one case of superficial infection, and reoperation was necessary in the two cases of septic arthritis. There were no neural, vascular and ligament injuries during surgery, and no complex regional pain syndrome, symptomatic deep vein thrombosis, and pulmonary embolism were observed.

Conclusion

Arthroscopic knee surgeries are considered to be minimally invasive, and are conducted relatively safe with low complication rates. In this series, however, seven cases of complications occurred, including two cases (0.08 %) of septic arthritis. Furthermore, symptomatic thromboembolism has been reported to occur also in arthroscopic surgery. The risk of severe complications has to be acknowledged.     

Effect of varus and valgus alignment on implant loading after proximal femur fracture fixation

Introduction

More than 10 % of proximal femur fractures repaired with either a sliding hip screw and side plate (SHS-P) or a sliding hip screw and intramedullary nail (SHS-IMN) demonstrate varus malreduction. The purpose of this study was to compare the effect of varus or valgus loading on comminuted intertrochanteric fractures repaired with SHS-P or SHS-IMN constructs.

Methods

Unstable intertrochanteric fractures with segmental comminution were generated in 12 cadaver proximal femurs, six of which were fixed with an SHS-P and six with an SHS-IMN. Both implants had a strain gauge at the lag screw-nail–plate interface to assess implant load bearing. The load on the implants was measured with the specimens in neutral position and at 5°, 10°, and 15° of varus and valgus.

Results

Loads on both SHS-IMN and SHS-P constructs were significantly increased when loading the implants in varus and significantly decreased when loading the implants in valgus. Unlike the SHS-IMN, the SHS-P trended toward increased load bearing at 15° varus (159.1 vs. 118.5 %, P = .065) and trended toward less load bearing at 15° valgus (42.3 vs. 59.8 %, P = .06). Conclusions: Regardless of implant choice, avoiding varus loading on the fixation construct reduces the load on the implant. SHS-P constructs may be more affected by varus or valgus malalignment than SHS-IMN constructs.

     

Management von Kombinationsfrakturen des Femurschafts und des proximalen Femurs

Purpose

The combination of ipsilateral femoral neck and shaft fractures remains a treatment challenge in orthopedic surgery because both fracture types constitute separate entities and require specific treatment concepts.

Material and methods

In a case control study, incidence, treatment strategies, and outcomes of this injury were analyzed. All patients with femoral fractures treated between 1 January 2001 and 31 July 2007 at a level I trauma center were included in the study.

Results

Twenty-one out of 1,935 patients (1.1%) sustained 22 combined fractures of the femoral neck and shaft. Also considering the combination of femoral shaft fractures with fractures of the acetabulum and the distal femur (knee), the proportion of chain injuries of the femur was 3.1%. The rate of multiply injured patients in the group of patients with ipsilateral femoral neck and shaft fractures was 64%. The majority of the patients could be treated with a single implant for both fracture components. The leading fracture component was the femoral neck fracture in eight cases. All fractures consolidated after 4.7 months on average; one pseudarthrosis of the femoral neck was observed. All fractures were discovered in the course of primary diagnostic measures; in 73% of the patients, a computed tomography (CT) body scan was done. Fifty-nine percent of the patients with ipsilateral femoral neck and shaft fractures received primary definitive operative care. Complications included two torsional failures that needed correction and one case of postoperative infection that was easily treated.

Conclusion

Treatment of ipsilateral femoral neck and shaft fractures is still demanding, but diagnosis has improved with regular use of CT body scans in the management of multiply injured patients. Furthermore, possibilities for operative treatment have been advanced by the introduction of the long proximal femoral nail and the antegrade femoral nail, two implants supporting stabilization of these fracture entities.     

Preoperative Valgus Alignment Does Not Predict Inferior Outcome of Total Knee Arthroplasty

Background

Preoperative valgus deformity is present in an estimated 10–20% of patients undergoing total knee replacement (TKR).

Questions/Purposes

The objective of this study was to compare the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores after TKR in a matched cohort of patients with preoperative valgus and varus deformities.

Methods

This is a matched cohort study of 162 patients with varus native knees and 162 patients with valgus native knees who underwent TKR and were prospectively followed in our institutional registry. Patients matched were based on age, BMI, sex, and severity of preoperative knee deformity, which was classified as mild, moderate, severe varus or valgus, or no deformity. Outcomes were evaluated using the WOMAC preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively.

Results

No significant difference was found between the matched varus and valgus cohorts in all WOMAC subdomain scores except for a marginally worse stiffness at 1 year in patients with valgus deformity (WOMAC stiffness, 75.1 varus vs. 70.1 valgus; P = 0.049). This is below the minimal clinically important difference for WOMAC scores. There was no significant difference in postoperative varus/valgus alignment between the two groups (P = 0.092)

Conclusion

We found no clinically significant difference in any of the WOMAC domains in patients with preoperative varus deformity versus valgus deformity within the first year after TKR. These findings may allow surgeons to more appropriately counsel patients with osteoarthritis with valgus deformity that they can expect similar outcomes compared to patients with varus deformity.

     

Algorithm for the management of femoral shaft fractures in children

Purpose

Pediatric closed femoral shaft fractures are commonly related to a good prognosis. There is no consensus on treatment. We aimed to evaluate the treatment, features, radiological findings and management strategies, creating an algorithm of treatment.

Materials and methods

Fifty-two simple femoral shaft fractures in children were retrospectively evaluated for age and gender distribution, side of the fracture, etiology of injuries, limb length discrepancy, range of knee and hip motion and parents satisfaction with a mean clinical and radiographic follow-up of 3 years and 6 months. Twenty-eight patients were treated with reduction and early hip spica cast while 24 patients were treated with external fixation (EF).

Results

Nearly 58 % of the cases were caused by traffic accidents and were predominantly male (61.5 %). Most of the fractures were of the middle femoral shaft (57.6 %). Muscle strength was normal (MRC scale) in all patients with no pain (NIPS and PRS scale). Knee and Hip range of motion were similar in both types of treatment. Patients treated with EF had shorter limb length discrepancy compared with SC. There were no reports of re-fracture. We found a higher familiar satisfaction in patients treated with EF.

Conclusions

An algorithm for the management of femoral shaft fractures in the pediatric population is proposed. Results on the study population gave raise to a satisfactory clinical and radiological results.     

The association between meniscal subluxation and cartilage degeneration

Purpose

The menisci play a critical protective role for the knee joint through shock absorption and load distribution. We hypothesized that cartilage degeneration will be abruptly progressed if meniscal subluxation exceeds a critical point.

Methods

Of 56 cases that showed medial meniscal subluxation without cartilage degeneration of ipsilateral medial femoral condyle (MFC) on initial MRI, from January 2005 to June 2007, meniscal subluxation index (MSI), the ratio of meniscal overhang to meniscal width in mid-coronal image of initial MRI, was measured. After 2 years, 40 cases were evaluated for cartilage degeneration of ipsilateral MFC on follow-up MRI. The relationship between medial MSI on initial MRI and cartilage degeneration of MFC on follow-up MRI was analyzed. Logistic regression analysis was conducted to find a critical point of meniscal subluxation related to cartilage degeneration.

Results

Abrupt progression of cartilage degeneration was observed from which MSI was 0.38. Logistic regression showed that if MSI was at the critical point, which was 0.38 in our study, then the probability of cartilage degeneration to grade 3 or 4 after 2 years was 44 %. If MSI was 0.4, then the probability was 50 %. If MSI was 0.6, then the probability was 99 %.

Conclusions

The results suggest the existence of critical point from which the protective function of the meniscus appears to be significantly altered, and the degree of cartilage degeneration of ipsilateral femoral condyle corresponding to the amount of medial meniscal subluxation may be predictable.     

Offene Rekonstruktion von Radiusköpfchenfrakturen mit und ohne begleitende Bandinstabilität

Background

The treatment of fractures of the radial head is commonly based on the Mason classification. Fractures of the radial head caused by a dislocation of the elbow are summarized as Mason type IV fractures. The purpose of this study was to investigate the outcome and the influence of additional ligamentous injuries after reconstruction of fractures of the radial head.

Patients and methods

One hundred three patients with a fracture of the radial head were treated by open reduction and internal fixation between 2004 and 2009. Fifty-eight of them could be evaluated at an average of 3.6 years after surgery. Forty-one patients had no additional ligamentous injury and 17 had a fracture combined with complete dislocation of the elbow. At the final follow-up examination, all patients were assessed clinically, bilateral radiographs were taken, and the Broberg and Morrey and Kellgren & Lawrence scores were determined.

Results

Ten patients had a Mason type II, 31 a Mason type III and 17 a Mason type IV fracture. With regard to the Broberg and Morrey score, patients without ligamentous injury achieved a significantly better functional outcome, with good to excellent results in 97.5% of cases compared to 64.6% for patients with ligamentous injuries. Twelve percent of the patients without ligamentous injury and 47% of the patients with ligamentous injuries developed moderate or severe posttraumatic arthritis. Heterotopic ossification was found in 19.5% of the patients without and in 47% of those with ligamentous injury.

Conclusion

Reconstruction of radial head fractures without ligamentous instability led to significantly superior functional results and lower rates of posttraumatic arthritis and heterotopic ossifications than osteosynthesis of fractures with additional ligamentous injury. In these cases primary endoprosthetic replacement might be considered.     

Usefulness of knee arthroscopy for diagnosis of knee pain in pediatric patients: comparison with preoperative clinical diagnosis

Purpose

To investigate the knee arthroscopic findings of pediatric patients with knee pain.

Subjects

Ninety-five knees of 94 patients (46 males and 48 females) aged 15 years or younger who underwent knee arthroscopy during a 4-year period from January 2007 were studied. The mean age at surgery was 13.5 (7–15) years. The mean interval from symptom onset to arthroscopic examination was 6.8 months (5 days to 2 years 10 months).

Results

The most common cause of knee pain was sports-related activities (64 knees). Other causes included falling from a moving bicycle (5 knees), while knee pain appeared with no defined reason in 14 knees. The most frequent final diagnosis based on knee arthroscopic findings was anterior cruciate ligament (ACL) injury (35 knees), followed by discoid lateral meniscus (16 knees), lateral meniscal tear (11 knees), and medial plica syndrome (9 knees), while no arthroscopic abnormality was observed in 8 of 95 knees. Among the 95 knees, the diagnosis based on preoperative physical tests and imaging findings was different from the arthroscopic diagnosis in 16 knees, 8 of which were diagnosed preoperatively as medial meniscal tear.

Conclusion

ACL injury and discoid lateral meniscus were the predominant conditions in pediatric patients who underwent knee arthroscopic surgery for knee pain. Knee arthroscopy is useful to provide a definitive diagnosis for knee pain in pediatric patients. Preoperative evaluations had a diagnostic accuracy of only 83.2 % and failed to diagnose conditions such as medial plica syndrome and chondral injury. Therefore, diagnosis before knee arthroscopy has to be interpreted with caution.     

Surgical Treatment of Tibial Plateau Fractures

Objective

Closed reduction of Schatzker type 4, 5, and 6 fractures of the tibial plateau, internal fixation by lag screws inserted through a mini-incision, and stabilization with Ilizarov external ring fixator.

Indications

Fractures of the tibial plateau of Schatzker type 4, 5, and 6.

Contraindications

Open infected tibial plateau fractures. Relative contraindications are Schatzker type 1, 2, and 3 fractures of the tibial plateau which can be treated by simpler methods.

Surgical Technique

Reduction of fracture by longitudinal traction on a frature table. Percutaneous insertion of two or three 6.5-mm lag screws to compress the major fragments. Stabilization of the fracture with a three-ring construction of the Ilizarov frame. Further compression of fragments with olive wires, used also to reduce and compress posterolateral and/or posteromedial fragments. The frame is ex-tended to the femur in instances of subluxation of the knee joint, ligamentous injuries, and associated femoral condylar fractures.

Results

Between 1991–1997, 56 patients were operated on. Aver-age follow-up: 3 years. Union occurred in all. Six patients showed a varus deformity of 5–10° and one a varus deformity of 15° four patients had an extension lag between 5–10°. A minor pin tract infection was observed 20 times and a major pin tract infection three times necessitating pin removal. One patient who suffered a compound fracture complicated by aseptic arthritis eventually required an arthrodesis. Applying the score of the American Knee Society, an excellent result was obtained 20 times, a good result 28 times, a fair one four times, and a poor one four times.     

Radial Head Reconstruction in Elbow Fracture-Dislocation: Monopolar or Bipolar Prosthesis?

Background

Monopolar and bipolar radial head prosthetic arthroplasties have been used successfully to treat elbow fracture-dislocation with unsalvageable radial head fractures. The relative stability of these two designs in different clinical situations is a topic of ongoing investigation.

Questions/purposes

We tested the effects of monopolar and bipolar fixed-neck prosthetic radial head implants on improvement in elbow coronal and axial plane laxity in a terrible triad biomechanical model that accounted for lateral collateral ligament integrity and the presence of a transverse coronoid fracture.

Methods

Kinematic data were collected on six fresh-frozen cadaveric upper extremities tested with passive motion throughout the flexion arc. Varus and valgus gravity stress were applied with the wrist in neutral position. A lateral collateral ligament reconstruction was simulated. We assessed instability after radial head resection and reconstruction with either a monopolar or bipolar implant in the presence of a transversely fractured (Regan and Morrey Type 2) or fixed coronoid process.

Results

With collateral ligament integrity, no difference was detected, with the numbers available, in valgus laxity between implants under valgus stress (p = 1.0). Laxity improvement with each prosthesis was higher when the coronoid was fractured (mean ± SD: monopolar: 7.4° ± 1.6°, p < 0.001; bipolar: 6.4° ± 1.6°, p = 0.003) than when it was fixed (monopolar: 4.0° ± 1.6°, p = 0.02; bipolar: 4.2° ± 1.6°, p = 0.01). With the numbers available, there was no difference in external rotation laxity between implants under valgus stress (p = 1.0). The greatest stabilizing effect of the prostheses occurred when the coronoid was fractured (monopolar: 3.3° ± 1.2°, p = 0.15; bipolar: 3.3° ± 1.2°, p = 0.17). Radial head arthroplasty offered no substantial stability under varus stress for varus or internal rotation laxity.

Conclusions

In our terrible triad cadaveric model, coronoid fixation was effective in improving varus laxity with a monopolar or bipolar prosthesis in place. Also, both types of prostheses were effective in improving valgus and external rotation laxity to the elbow, regardless of coronoid status. With collateral ligaments reconstructed, no large kinematic differences were noted between implants regardless of the varus-valgus position or whether the coronoid was fractured or fixed.

Clinical Relevance

The data from our cadaveric model support the use of either implant type in terrible triad injuries if the collateral ligaments are intact or reconstructed.     

The effect of inferomedial screw on postoperative shoulder function and mechanical alignment in proximal humerus fractures

Aim

The aim of the study was to evaluate the clinical and radiologic results of locking plate fixation with or without inferomedial screw (IMS) in surgically treated proximal humerus fractures.

Patients and methods

Thirty-six patients with displaced proximal humerus fractures from two centers were operated using locking plate. All of the fractures were classified according to the Neer classification. In 18 of the cases, an additional IMS running through the medial curvature of the surgical neck was used. There was no significant difference among both groups in terms of height, gender, weight, and mechanism of injury. The fractures were evaluated according to the radiographic and functional findings during follow-up period of 14 months in average (range 8–32 months). At the end of first year, shoulder radiographs were received and shoulder examinations were performed using ASES scores. Humeral head-shaft angles were measured by true AP projections. Head-shaft angle measurements were categorized as varus if <125, normal if between 125 and 145, and valgus if >145.

Results

Mean time for fracture healing was 18 weeks. Complete union was achieved in 35 patients by the end of 6 months. In one of the 18 displaced proximal humerus fractures of IMS (+) group, the head-shaft angle was measured to be <125, whereas six patients had varus deviation in IMS (?) group at follow-up (p < 0.05). Mean ASES scores of IMS (+) group and IMS (?) group were 58.21 ± 5.82 and 38.61 ± 3.44, respectively (p < 0.001).

Conclusion

Use of inferomedial screw running through the medial curvature of surgical neck prevents varus deformity and improves functional outcome after surgical treatment for proximal humerus fractures.     

Moderne unikondyläre Kniearthroplastik

Background

Unicondylar knee arthroplasty (UKA) is an established therapeutic option for advanced medial or lateral gonarthrosis.

Objectives

The cornerstones of a successful UKA, careful patient selection, preoperative planning and precise operation technique, are discussed in this overview article.

Importance

In contrast to total knee arthroplasty, UKA allows preservation of the contralateral and patellofemoral compartments as well as the cruciate ligaments and is often associated with rapid postoperative recovery, improved knee kinematics and knee function. However, UKA is technically very demanding. High revision rates have been reported in particular with widespread application, according to national joint replacement registries.

Conclusion

Successful UKA relies on meticulous patient selection, preoperative planning and surgical technique. It is justified to broaden classic UKA indications. In medial and lateral UKA three types of mechanical varus-valgus deformity can be encountered: type 1 (isolated intraarticular deformity), type 2 (pronounced deformity due to extraarticular varus deformity in medial UKA or valgus deformity in lateral UKA), type 3 (reduced deformity due to extraarticular valgus deformity in medial UKA or varus deformity in lateral UKA). We believe these deformities should be addressed accordingly with surgical technique.     

Integrating various common indexes of bony alignment in femoral supracondyle

Objective

Indexes, which can optimally represent the bony alignment around the knee, are still controversial. Three common indexes, mechanical axis (MA), anatomic axis (AA), and anatomic lateral distal femoral angle (aLDFA), were integrated to simplify patient follow-up in the femoral supracondylar region.

Materials and methods

Eighty consecutive adult patients (40 men, 40 women; age range 19–40 years) were studied using a full-length standing scanogram. Thirteen indexes, including MA, AA, and aLDFA, were measured and integrated. The relationships among these indexes were analyzed.

Results

The MA of the lower extremity passed with an average of 6.6 mm (9.2 % of the tibial articular surface width) medial to the knee center. The supracondylar axis (SA) was an average of 2.0° more valgus than the AA in the femoral supracondyle. An average 1.1° deviation was noted in the AA, as measured by the femoral shaft axis or a line connecting the piriformis fossa to the knee center.

Conclusion

The femoral MA may be more favorable than the MA of the lower extremity in order to represent an ideal weight-bearing line. The AA and aLDFA may be measurable via the SA in the anteroposterior view of the plain knee radiograph. Thus, patient follow-up becomes much more convenient.     

Outcomes of long retrograde intramedullary nailing for periprosthetic supracondylar femoral fractures following total knee arthroplasty

Background

The treatment of periprosthetic supracondylar femoral fractures following total knee arthroplasty (TKA) is challenging because of osteopenia and the limited bone available for distal fixation. The purpose of this study was to report the outcomes of periprosthetic supracondylar femoral fractures treated with long retrograde intramedullary nailing.

Methods

We conducted a retrospective review of 25 patients who were treated with a long retrograde intramedullary nail for periprosthetic supracondylar femoral fractures following TKA. Clinical evaluation included range of motion of knee, Knee Society Score (KSS), Western Ontario and McMaster Universities Arthritis (WOMAC) score, and radiologic evaluation including time to union, coronal and sagittal alignment of femoral component, lower limb alignment, and implant loosening. The mean duration of follow-up after the fracture repair was 39 months (range 12–47).

Results

All 25 fractures were united with a mean time of 12 weeks (range 8–20). At the last follow-up, the mean knee flexion was 111° (range 60°–130°), the mean KSS was 81.5 (range 50–100), and the mean WOMAC score was 30.2 (range 5–55). Four (16 %) of the 25 patients developed malalignment according to Rorabeck and Taylor criteria, but all patients had a knee flexion of more than 90°. Coronal and sagittal alignments of femoral component and lower limb alignment did not differ significantly between before and after the fracture repair. Complications included the loosening or breakage of distal interlocking screws in three patients. No deep infection or prosthesis loosening was detected at the last follow-up.

Conclusions

Surgical treatment of periprosthetic supracondylar femoral fractures following TKA with long retrograde intramedullary nailing resulted in high union rates and encouraging functional outcomes.