Management after acute rupture of the anterior cruciate ligament (ACL). Part 1: ACL reconstruction has a protective effect on secondary meniscus and cartilage lesions

PURPOSE

The aim of this consensus project was to validate which endogenous and exogenous factors contribute to the development of post-traumatic osteoarthritis and to what extent ACL (anterior cruciate ligament) reconstruction can prevent secondary damage to the knee joint. Based on these findings, an algorithm for the management after ACL rupture should be established.

METHODS

The consensus project was initiated by the Ligament Injuries Committee of the German Knee Society (Deutsche Kniegesellschaft, DKG). A modified Delphi process was used to answer scientific questions. This process was based on key topic complexes previously formed during an initial face-to-face meeting of the steering group with the expert group. For each key topic, a comprehensive review of available literature was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Consensus was defined a-priori as eighty percent agreement.

RESULTS

Of the 17 final statements, 15 achieved consensus, and 2 have not reached consensus. Results of the consensus were summarized in an algorithm for the management after ACL rupture (infographic/Fig. 2).

CONCLUSION

This consensus process has shown that the development of post-traumatic osteoarthritis is a complex multifactorial process. Exogenous (primary and secondary meniscus lesions) and endogenous factors (varus deformity) play a decisive role. Due to the complex interplay of these factors, an ACL reconstruction cannot always halt post-traumatic osteoarthritis of the knee. However, there is evidence that ACL reconstruction can prevent secondary joint damage such as meniscus lesions and that the success of meniscus repair is higher with simultaneous ACL reconstruction. Therefore, we recommend ACL reconstruction in case of a combined injury of the ACL and a meniscus lesion which is suitable for repair.

LEVEL OF EVIDENCE

Level V.

Iatrogenic instability of the acromioclavicular joint leads to ongoing impairment of shoulder function even following secondary surgical stabilization

PURPOSE

Iatrogenic instability of the acromioclavicular joint (ACJ) following distal clavicle excision (DCE) represents an infrequent pathology. Revision surgery to restore ACJ stability and alleviate concomitant pain is challenging due to altered anatomic relationships. The purpose of this study was to evaluate the used salvage techniques and postoperative functional and radiological outcomes in retrospectively identify patients with a painful ACJ following DCE. We hypothesized that iatrogenic instability leads to ongoing impairment of shoulder function despite secondary surgical stabilization.

METHODS

9 patients with a painful ACJ after DCE (6 men, 3 women, 43.3 ± 9.4 years) were followed up at a minimum of 36 months after revision surgery. Besides range of motion (ROM), strength and function were evaluated with validated evaluation tools including the Constant score and the DASH score (Disability of the Arm, Shoulder and Hand questionnaire), specific AC Score (SACS), Nottingham Clavicle Score (NCS), Taft score and Acromioclavicular Joint Instability Score (AJI). Additionally, postoperative X-rays were compared to the unaffected side, measuring the coracoclavicular (CC) and acromioclavicular (AC) distance.

RESULTS

At follow-up survey (55.8 ± 18.8 months) all patients but one demonstrated clinical ACJ stability after arthroscopically assisted anatomical ACJ reconstruction with an autologous hamstring graft. Reconstruction techniques were dependent on the direction of instability. The functional results demonstrated moderate shoulder and ACJ scores with a Constant Score of 77.3 ± 15.4, DASH-score of 51.2 ± 23.4, SACS 32.6 ± 23.8, NCS 77.8 ± 14.2, AJI 75 ± 14.7 points and Taft Score 7.6 ± 3.4 points. All patients stated they would undergo the revision surgery again. Mean postoperative CC-distance (8.3 ± 2.8 mm) did not differ significantly from the contralateral side (8.5 ± 1.6 mm) (p > 0,05). However, the mean AC distance was significantly greater with 16.5 ± 5.8 mm compared to the contralateral side (3.5 ± 1.9 mm) (p = 0.012).

CONCLUSION

Symptomatic iatrogenic ACJ instability following DCE is rare. Arthroscopically assisted revision surgery with an autologous hamstring graft improved ACJ stability in eight out of nine cases (88.9%). However, the functional scores showed ongoing impairment of shoulder function and a relatively high overall complication rate (33.3%). Therefore, this study underlines the importance of precise preoperative indication and planning and, especially, the preservation of ACJ stability when performing AC joint resection procedures.

LEVEL OF EVIDENCE

Case series, LEVEL IV.

Patient satisfaction, joint stability and return to sports following simple elbow dislocations: surgical versus non-surgical treatment

PURPOSE

While conservative management is commonly promoted for simple elbow dislocations, the importance of primary surgical treatment in these injuries is still undetermined. The objective of this study was to report patient-reported outcome measures (PROMs), return to sports (RTS) and joint stability using ultrasound in patients following conservative or surgical treatment after simple elbow dislocation.

METHODS

Patients with a minimum follow-up of 24 months after conservative (CT) or surgical treatment (ST) following simple elbow dislocation were included in this retrospective study. To evaluate patients' postoperative outcome and satisfaction, the Elbow Self-Assessment Score (ESAS) was used, and validated scores such as the Mayo elbow performance score (MEPS), the Quick Disability of Arm and Shoulder Score (Quick-DASH) and RTS were assessed. For objective assessment of residual joint instability, a standardized clinical examination as well as a dynamic ultrasound evaluation of the affected and the contralateral elbow was performed.

RESULTS

Forty-four patients (26 women, 18 men) with an average age of 41.5 ± 15.3 years were available for follow-up survey (65.5 ± 30.4 months; range 26-123). 21 patients were treated conservatively and twenty-three patients received surgical treatment. CT and ST resulted in similar outcome with regard to ROM, ESAS (CT: 99.4 ± 1.5; ST: 99.8 ± 0.3), MEPS (CT: 97.3 ± 6.8 points; ST: 98.7 ± 3.3) and Quick-DASH (CT: 7.8 ± 10.4; ST: 6.3 ± 7.9) (n.s.). There was no difference in elbow stability and laxity measured by ultrasound between the study groups and compared to the healthy elbow (n.s.). Two patients of the CT group (10%) complained about persistent subjective elbow instability. RTS was faster after surgical compared to conservative treatment (p = 0.036).

CONCLUSION

Both, conservative and surgical treatment results in high patient satisfaction and good-to-excellent functional outcome after simple elbow dislocation. Even though ultrasound evaluation showed no significant differences in joint gapping between groups, 10% of conservatively treated patients complained about severe subjective instability. Surgically treated patients returned faster to their preoperatively performed sports. Thus, primary surgical treatment may be beneficial for high demanding patients.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

Reliable ligamentous stability and high return-to-sport rates after arthroscopic reduction and internal fixation of tibial eminence fractures

PURPOSE

To investigate functional and clinical outcomes, and physical activity after arthroscopic suture fixation of tibial eminence fractures with regard to postoperative stability, range of motion (ROM), complications, and return to sports.

METHODS

Patients undergoing arthroscopic reduction and internal fixation (ARIF) of tibial eminence fractures using a suture fixation technique were included. Outcome was evaluated retrospectively after a minimum follow-up of 24 months using KT-1000 arthrometer measurements, clinical examination, outcome scores (Lysholm score, Tegner Activity Scale), and a questionnaire about sport activities.

RESULTS

A total of 23 patients (44% male, 57% female) with a mean age of 25 ± 15 years were included. Mean follow-up was 57 ± 25 months. KT-1000 arthrometer measurements of anterior tibial translation revealed a mean side-to-side difference of 0.9 ± 1.0 mm. Clinical examination showed 100% normal or nearly normal anterior translation of the tibia. Two patients (9%) received an ACL reconstruction due to traumatic ACL re-instability and were, therefore, considered as failures. An extension deficit concerning hyperextension occurred in 29% of patients postoperatively. Further postoperative complications occurred in 14% of patients and included postoperative stiffness with ROM limitations and secondary dislocation of a fragment. Mean postoperative Lysholm score was 89 ± 14. Comparing pre- and postoperative values, no significant change of the Tegner Activity Scale was observed. All patients (failures excluded) returned to high impact sports activities after ARIF.

CONCLUSION

Excellent reliable ligamentous stability and high rates of return to high impact sports can be expected after ARIF using a suture fixation technique for type II-IV tibial eminence fractures. Complications, such as limitations in ROM, commonly occur in up to 30% after ARIF. Therefore, regular follow-up examinations remain important in this usually young patient cohort.

LEVEL OF EVIDENCE

Level IV.

Distal biceps tendon ruptures occur with the almost extended elbow and supinated forearm - an online video analytic study

Background

Distal biceps tendon ruptures can lead to significant restrictions in affected patients. The mechanisms of injury described in scientific literature are based exclusively on case reports and theoretical models. This study aimed to determine the position of the upper extremities and forces involved in tendon rupture through analyzing video recordings.

Methods

The public YouTube.com database was queried for videos capturing a clear view of a distal biceps tendon rupture. Two orthopedic surgeons independently assessed the videos for the activity that led to the rupture, the arm position at the time of injury and the forces imposed on the elbow joint.

Results

Fifty-six video segments of a distal biceps rupture were included (55 male). In 96.4%, the distal biceps tendon ruptured with the forearm supinated and the elbow isometrically extended (non-dynamic muscle engagement) (71.4%) or slightly flexed (24%). The most common shoulder positions were adduction (85.7%) and neutral position with respect to rotation (92.9%). Most frequently a tensile force was enacted on the elbow (92.9%) and the most common activity observed was deadlifting (71.4%).

Conclusion

Distal biceps tendon ruptures were most commonly observed in weightlifting with a slightly flexed or isometrically extended elbow and forearm supination. These observations may provide useful information for sports specific evidence-based injury prevention, particularly in high performing athletes and individuals engaged in resistance training.

Level of evidence

Observational study.

Anterior cruciate ligament autograft maturation on sequential postoperative MRI is not correlated with clinical outcome and anterior knee stability

PURPOSE

Magnetic resonance imaging (MRI) signal intensity is correlated to structural postoperative changes of the anterior cruciate ligament (ACL) autograft. The purpose of this study was to investigate the ACL autograft maturation process via MRI over 2 years postoperatively, compare it to a native ACL signal and correlate the results with clinical outcome, return to preinjury sports levels, and knee laxity measurements.

METHODS

ACL autograft signal intensity was measured in 17 male patients (age, 28.3 ± 7.0 years) who underwent ACL reconstruction with hamstring autograft at 6 weeks, 3-, 6-, 12-, and 24 months postoperatively by 3 Tesla MRI. Controls with an intact ACL served as control group (22 males, 8 females; age, 26.7 ± 6.8 years). An ACL/PCL ratio (APR) and ACL/muscle ratio (AMR) was calculated to normalize signals to soft tissue signal. APR and AMR were compared across time and to native ACL signal. Clinical outcome scores (IKDC, Lysholm), return to preinjury sports levels (Tegner activity scale), and knee laxity measurement (KT-1000) were obtained and correlated to APR and AMR at the respective time points.

RESULTS

The APR and AMR of the ACL graft changed significantly from the lowest values at 6 weeks to reach the highest intensity after 6 months (p < 0.001). Then, the APR and AMR were significantly different from a native ACL 6 months after surgery (p < 0.01) but approached the APR and AMR of the native ACL at 1- and 2 years after surgery (p < 0.05). The APR changed significantly during the first 2 years postoperatively in the proximal (p < 0.001), mid-substance (p < 0.001), and distal (p < 0.01) intraarticular portion of the ACL autograft. A hypo-intense ACL MRI signal was associated with return to the preinjury sports level (p < 0.05). No correlation was found between ACL MRI graft signal and clinical outcome scores or KT-1000 measurements.

CONCLUSION

ACL grafts undergo a continuous maturation process in the first 2 years after surgery. The ACL graft signals became hyper-intense 6 months postoperatively and approximated the signal of a native intact ACL at 12- and 24 months. Patients with a hypo-intense ACL graft signal at 2 years follow-up were more likely to return to preinjury sports levels. The results of the present study provide a template for monitoring the normal ACL maturation process via MRI in case of prolonged clinical symptoms. However, subjective outcome and clinical examination of knee laxity remain important to assess the treatment success and to allow to return to sports.

LEVEL OF EVIDENCE

III.

Combined posterolateral knee reconstruction: ACL-based injuries perform better compared to PCL-based injuries

PURPOSE

To compare post-operative physical activity and return to work after combined posterolateral corner (PLC) reconstruction (PLC-R) in anterior cruciate ligament (ACL)- or posterior cruciate ligament (PCL)-based injuries.

METHODS

Patients aged > 18 years undergoing PLC-R using the Larson technique combined with either ACL or PCL reconstruction were included. Outcome was evaluated retrospectively after a minimum follow-up of 24 months using Tegner Activity Scale, Activity Rating Scale (ARS), Knee Injury and Osteoarthritis Outcome Score (KOOS), work intensity according to REFA classification, and a questionnaire about type of occupation and time to return to work.

RESULTS

A total of 32 patients (11 ACL-based injuries and 21 PCL-based injuries) were included. Mean follow-up was 56 ± 26 months in the ACL-based injury group and 59 ± 24 months in the PCL-based injury group. All patients in the ACL-based injury group and 91% of patients in the PCL-based injury group returned to sports activities. Comparing pre- and post-operative values, a significant deterioration of the Tegner Activity Scale and ARS was observed in the PCL-based injury group, whereas no significant change was observed in the ACL-based injury group. KOOS subscales were generally higher in the ACL-based injury with significant differences in the subscale sports and recreational activities. Patients with ACL-based injuries returned to work significantly earlier compared to patients with PCL-based injuries (11 ± 4 weeks vs. 21 ± 10 weeks, p < 0.05).

CONCLUSION

High rates of return to sports and work can be expected after combined PLC-R in both ACL- and PCL-based injuries. However, deterioration of sports ability must be expected in PCL-based injuries. ACL-based injuries led to superior patient-reported outcomes and an earlier return to work, as compared to PCL-based injuries.

LEVEL OF EVIDENCE

Level IV.

Ultrasound-based evaluation revealed reliable postoperative knee stability after combined acute ACL and MCL injuries

Purpose

Anterior cruciate ligament (ACL) injuries are often combined with lesions of the medial collateral ligament (MCL). The aim of this study was to evaluate treatment outcome of combined acute ACL and MCL lesions using functional US and clinical examination.

Methods

Patients aged > 18 years undergoing primary ACL reconstruction with concomitant operative (group 1) or non-operative treatment of the MCL (group 2) between 2014 and 2019 were included after a minimum follow-up of 12 months. Grade II MCL injuries with dislocated tibial or femoral avulsions and grade III MCL ruptures underwent ligament repair whereas grade II injuries without dislocated avulsions were treated non-operatively. Radiological outcome was assessed with functional US examinations. Medial knee joint width was determined in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton) conditions using a fixation device. Clinical examination was performed and patient-reported outcomes were assessed by the use of the subjective knee form (IKDC), Lysholm score, and the Tegner activity scale.

Results

A total of 40 patients (20 per group) met inclusion criteria. Mean age of group 1 was 40 ± 12 years (60% female) with a mean follow-up of 33 ± 17 months. Group 2 showed a mean age of 33 ± 8 years (20% female) with a mean follow-up of 34 ± 15 months. Side-to-side differences in US examinations were 0.4 ± 1.5 mm (mm) in 0° and 0.4 ± 1.5 mm in 30° knee flexion in group 1, and 0.9 ± 1.1 mm in 0° and 0.5 ± 1.4 mm in 30° knee flexion in group 2, with no statistically significant differences between both groups. MCL repair resulted in lower Lysholm scores (75 ± 19 versus 86 ± 15; p < 0.05). No significant differences could be found for subjective IKDC or Tegner activity scores among the two groups.

Conclusion

A differentiated treatment concept in combined ACL and MCL injuries based on injury patterns leads to reliable postoperative ligamentous knee stability in US-based and clinical examinations. However, grade II and III MCL lesions with subsequent operative MCL repair (group 1) result in slightly poorer subjective outcome scores.

Level of evidence

Retrospective cohort study; Level III

Delayed proximal hamstring tendon repair after ischial tuberosity apophyseal fracture in a professional volleyball athlete: a case report

Background

Ischial tuberosity apophyseal fractures are avulsion fractures of the anatomic footprint of the proximal hamstring tendons. Generally, these injuries are rare and frequently occur in skeletally immature, active patients due to incomplete ossification. Depending on the fragment displacement, non-operative or operative treatment approaches are used.

Case presentation

We report a case of a 29-year-old professional volleyball athlete who has suffered from a nonunion avulsion fracture for 14 years. Isolated suture anchor fixation was performed after open excision of a large bony fragment followed by excellent clinical and functional outcome at 1 year postoperatively.

Conclusion

In conclusion, avulsion fractures of the ischial tuberosity with large fragments and restrictions to activities of daily living due to pain can, in individualized cases, be treated with an open excision of the fragment followed by repair of the proximal hamstring tendons using suture anchors.

Ultrasound-based examination of the medial ligament complex shows gender- and age-related differences in laxity

PURPOSE

Ultrasound (US) examination of the medial joint space of the knee has played a subordinate diagnostic role up till now. The purpose of the present study was to describe mean values of medial joint width and to investigate the impact of gender, age, and body mass index (BMI) on medial joint laxity in healthy knees using modern, dynamic US in a standardized fashion in unloaded and standardized loaded conditions.

METHODS

A total of 65 subjects with 79 healthy knees were enrolled in this study. All volunteers underwent clinical examination of the knee. The medial knee joint width was determined using US in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton, daN) conditions using a specific device. Mean values were described and correlations between medial knee joint width and gender, age, and BMI were assessed.

RESULTS

Thirty-two females and 33 males were enrolled in this study. The mean medial joint width in 0° unloaded was 5.7 ± 1.2 mm and 7.4 ± 1.4 mm loaded. In 30° of knee flexion, the mean medial joint width was 6.1 ± 1.1 mm unloaded and 7.8 ± 1.2 mm loaded. The average change between unloaded and loaded conditions in 0° was 1.7 ± 1.0 mm and in 30° 1.7 ± 0.9 mm. A significant difference between genders was evident for medial joint width in 0° and 30° of flexion in unloaded and loaded conditions (p < 0.05). With rising age, a significant increased change of medial joint space width between unloaded and loaded conditions could be demonstrated in 0° (p = 0.032). No significant correlation between BMI and medial joint width in US could be found.

CONCLUSION

Mean values of medial joint width in unloaded and standardized loaded conditions using a fixation device could be demonstrated. Based on the results of this study, medial knee joint width in US is gender- and age-related in healthy knees. These present data may be useful for evaluating patients with acute or chronic pathologies to the medial side of the knee.

LEVEL OF EVIDENCE

III.

Isolated high tibial osteotomy is appropriate in less than two-thirds of varus knees if excessive overcorrection of the medial proximal tibial angle should be avoided

PURPOSE

To perform a detailed deformity analysis of patients with varus alignment and to define the ideal osteotomy level (tibial vs. femoral vs. double level) to avoid an oblique joint line.

METHODS

A total of 303 digital full-leg standing radiographs of patients aged 18-60 years and varus alignment [mechanical tibiofemoral varus angle (mFTA) ≥ 3°] were included. All legs were analyzed regarding mFTA, mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femur angle (mLDFA), and joint line convergence angle. Based on mFTA, varus alignment was categorized as "mild" (3°-5°), "moderate" (6°-8°), or "severe" (≥ 9°). Deformity location was determined according to the malalignment test described by Paley. Two osteotomy simulations were performed with different upper limits for mMPTA: anatomic correction (mMPTA ≤ 90°, mLDFA ≥ 85°) and overcorrection (mMPTA ≤ 95°, mLDFA ≥ 85°). If a single osteotomy exceeded these limits at the intended mFTA of 2° valgus, a double-level osteotomy was simulated. If even a double-level osteotomy resulted in deviations from the defined limits, the leg was categorized as "uncorrectable".

RESULTS

Mean mFTA was 6° ± 11° of varus (range 3°-15°). A tibial deformity was observed in 28%, a femoral deformity in 23%, a combined tibial and femoral deformity in 4%, and no bony deformity in 45%. The prevalence of a tibial deformity did not differ between varus severity groups, whereas a femoral and bifocal deformity was significantly more prevalent in knees with more distinct varus (p < 0.001). Osteotomy simulation revealed that isolated high tibial osteotomy (HTO) was appropriate in only 12% for anatomic correction, whereas a double-level osteotomy was necessary in 63%. If overcorrection of mMPTA was tolerated, the number of HTOs significantly increased to 57% (p < 0.001), whereas the number of double-level osteotomies significantly decreased to 33% (p < 0.001). Isolated DFO was considered ideal in 8% for both simulations. Significantly more knees were considered "uncorrectable" by simulating anatomic correction (18 vs. 2%; p < 0.001). A double-level osteotomy was significantly more often necessary in knees with "severe" varus (p < 0.001).

CONCLUSION

Less than one-third of patients (28%) with mechanical varus ≥ 3° have a tibial deformity. If anatomic correction (mMPTA ≤ 90°) is intended, only 12% of patients can be corrected via isolated HTO, whereas 63% of patients require a double-level osteotomy. If slight overcorrection is accepted (mMPTA ≤ 95°), 57% of patients can be corrected via isolated HTO, whereas 33% of patients would still require a double-level osteotomy.

LEVEL OF EVIDENCE

III, cross-sectional study.

A hinge position distal to the adductor tubercle minimizes the risk of hinge fractures in lateral open wedge distal femoral osteotomy

PURPOSE

To evaluate the incidence and morphology of medial cortical hinge fractures in lateral open wedge distal femoral osteotomy (LOW-DFO) and to determine a safe zone for the position of the osteotomy hinge to minimize the risk of hinge fractures.

METHODS

Consecutive patients who underwent LOW-DFO for symptomatic valgus malalignment were screened for eligibility for this retrospective observational cohort study. Demographical and surgical data were collected. The incidence and morphology of medial cortical hinge fractures were evaluated on standard postoperative anterior-posterior knee radiographs. Comprehensive measurements evaluating the osteotomy gap and the position of the osteotomy hinge were taken. Additionally, each osteotomy hinge was assigned to a corresponding sector of a proposed five-sector grid of the distal medial femur.

RESULTS

A total of 100 patients (60% female) with a mean age of 31 ± 13 years were included. The overall incidence of medial cortical hinge fractures was 46% and three distinct fracture types were identified. The most frequently observed fracture type was extension of the osteotomy gap (76%), followed by a proximal (20%) and distal (4%) course of the fracture line in relation to the hinge. Group comparison (hinge fracture vs. no hinge fracture) showed statistically significant higher values for the height of the osteotomy gap (p = 0.001), the wedge angle (p = 0.036), and the vertical distance between the hinge and the proximal margin of the adductor tubercle (AT; p = 0.002) in the hinge fracture group. Furthermore, a significantly lower horizontal distance between the hinge and the medial cortical bone (p = 0.036) was observed in the hinge fracture group. A statistically significant higher incidence of medial cortical hinge fractures was observed when the position of the osteotomy hinge was proximal compared to distal to the proximal margin of the AT (53% vs. 27%; p = 0.023).

CONCLUSION

Medial cortical hinge fractures in LOW-DFO are a common finding with three distinct fracture types. To minimize the risk of medial cortical hinge fractures, it is recommended to aim for a position of the osteotomy hinge at the level of or distal to the proximal margin of the adductor tubercle.

LEVEL OF EVIDENCE

Prognostic study; Level III.

Increased external tibial torsion is an infratuberositary deformity and is not correlated with a lateralized position of the tibial tuberosity

PURPOSE

To perform a segmental analysis of tibial torsion in patients, with normal and increased external tibial torsion, suffering from chronic patellofemoral instability (PFI) and to investigate a possible correlation between tibial torsion and the position of the tibial tuberosity.

METHODS

Patients with chronic PFI who underwent torsional analysis of the lower limb using a standardized hip-knee-ankle MRI between 2016 and 2018 were included. For segmental analysis of tibial torsion, three axial levels were defined which divided the tibia into two segments: a distal, infratuberositary segment and a proximal, supratuberositary segment. Torsion was measured for the entire tibia (total tibial torsion, TTT), the proximal segment (proximal tibial torsion, PTT), and the distal segment (distal tibial torsion, DTT). Based on TTT, patients were assigned to one of two groups: Normal TTT (< 35°) or increased external TTT (> 35°). Position of the tibial tuberosity was assessed on conventional MRI scans by measuring the tibial tuberosity-trochlea groove (TT-TG) and the tibial tuberosity-posterior cruciate ligament (TT-PCL) distances.

RESULTS

Ninety-one patients (24 ± 6 years; 78% female) were included. Mean external TTT was 29.6° ± 9.1° and 24 patients (26%) had increased external TTT. Compared to patients with normal TTT, patients with increased external TTT demonstrated significantly higher values for DTT (38° ± 8° vs. 52° ± 9°; p < 0.001), whereas no difference was found for PTT ( - 13° ± 6° vs.  - 12° ± 6°; n.s.). Furthermore, a significant correlation was found between TTT and DTT (p < 0.001), whereas no correlation was found between TTT and PTT (n.s). With regard to TT-TG and TT-PCL distances, no significant differences were observed between the two groups (TT-TG: 15 ± 6 vs. 14 ± 4 mm, n.s.; TT-PCL: 22 ± 4 vs. 21 ± 5 mm, n.s.) and no correlation was found with TTT, DTT, or PTT (n.s.).

CONCLUSION

In patients with chronic PFI, increased external TTT of greater than 35° is an infratuberositary deformity and does not correlate with a lateralized position of the tibial tuberosity.

LEVEL OF EVIDENCE

Level III.

[Female doctors in orthopedics and trauma surgery in Germany: a current status quo]

BACKGROUND

Gender-specific differences in the workplace in general and in the field of orthopedics and trauma surgery in particular are still clearly identifiable, and are becoming more and more pronounced in the social consciousness.

OBJECTIVE

Analysis of the gender-specific development in the specialist field of orthopedics and trauma surgery in Germany over the past 15 years and a survey of the status quo.

METHODS

Assessment of the development of female graduates in the study of human medicine, the proportion of women in accredited and clinical care and the gender-specific acquisition of an additional orthopedic/trauma surgical title. Evaluation of gender-specific numbers of members or participants in the relevant professional associations and the largest German conferences on orthopedics and trauma surgery, as well as the habilitation figures in the field of orthopedics.

RESULTS AND DISCUSSION

The proportion of female doctors in various fields of orthopedics and trauma surgery in the clinic and in science is increasing. There is still a clear discrepancy in leading positions in clinics, in the acquisition of an additional title, and on the boards of professional associations. In some fields, such as pediatric and hand/foot/ankle surgery, the proportion of women is higher than in other sub-areas of orthopedics and trauma surgery.

Preoperative patellofemoral anatomy affects failure rate after isolated patellofemoral inlay arthroplasty

PURPOSE

To analyze whether preoperative patellofemoral anatomy is associated with clinical improvement and failure rate after isolated patellofemoral arthroplasty (PFA) using a modern inlay-type trochlear implant.

METHODS

Prospectively collected 24 months data of patients treated with isolated inlay PFA (HemiCAP^® Wave, Arthrosurface, Franklin, MA, USA) between 2009 and 2016, and available digitalized preoperative imaging (plain radiographs in three planes and MRI) were retrospectively analyzed. All patients were evaluated using the WOMAC score, Lysholm score, and VAS pain. Patients revised to TKA or not achieving the minimal clinically important difference (MCID) for the total WOMAC score or VAS pain were considered failures. Preoperative imaging was analyzed regarding the following aspects: Tibiofemoral OA, patellofemoral OA, trochlear dysplasia (Dejour classification), patellar height (Insall-Salvati index [ISI]; Patellotrochlear index [PTI]), and position of the tibial tuberosity (TT-TG and TT-PCL distance).

RESULTS

A total of 41 patients (61% female) with a mean age of 48 ± 13 years could be included. Fifteen patients (37%) were considered failures, with 5 patients (12%) revised to TKA and 10 patients (24%) not achieving MCID for WOMAC total or VAS pain. Failures had a significantly higher ISI, and a significantly lower PTI. Furthermore, the proportion of patients with a pathologic ISI (> 1.2), a pathologic PTI (< 0.28), and without trochlear dysplasia were significantly higher in failures. Significantly greater improvements in clinical outcome scores were observed in patients with a higher preoperative grade of patellofemoral OA, ISI ≤ 1.2, PTI ≥ 0.28, TT-PCL distance ≤ 21 mm, and a dysplastic trochlea.

CONCLUSION

Preoperative patellofemoral anatomy is significantly associated with clinical improvement and failure rate after isolated inlay PFA. Less improvement and a higher failure rate must be expected in patients with patella alta (ISI > 1.2 and PTI < 0.28), absence of trochlear dysplasia, and a lateralized position of the tibial tuberosity (TT-PCL distance > 21 mm). Concomitant procedures such as tibial tuberosity transfer may, therefore, be considered in such patients.

LEVEL OF EVIDENCE

Level III, retrospective analysis of prospectively collected data.

A role for oxidative stress in suppressing serum immunoglobulin levels in lead-exposed Fisher 344 rats

Evidence implicating oxidative stress in toxicity during lead intoxication in vivo has opened new avenues for investigation of the mechanisms of lead-induced immunosuppression. The current study explores the possibility that lead-induced oxidative stress contributes to the immunosuppression observed during lead poisoning. Fisher 344 rats were exposed to 2,000 ppm lead acetate in their drinking water for 5 weeks. One week following removal of lead from the drinking water, significant reductions in serum levels of IgA, IgM, and IgG were detected. Significant increases in oxidative damage, based on malondialdehyde (MDA) content, were observed in peripheral blood mononuclear cells (PMCs) collected during the same experiments. In addition, MDA content increased in livers from lead-exposed rats. Following 5 weeks of lead exposure, administration of either 5.5 mmol/kg N-acetylcysteine (NAC) or 1 mmol/kg meso-2,3-dimercaptosuccinic acid (DMSA) in the drinking water for 1 week significantly reversed the inhibitory effects of lead on serum immunoglobulin (Ig) levels. Also, all parameters indicative of oxidative stress returned to control levels. These results suggest that oxidative stress contributes to suppressed serum Ig levels during lead intoxication in vivo, and that intervention with either a thiol antioxidant (NAC) or a metal chelator (DMSA) will alleviate this lead-induced suppression by correcting the prooxidant/antioxidant imbalance caused by lead exposure.

Elevated immunoglobulin E (IgE) levels in children with exposure to environmental lead

Lead has been reported to be an immunosuppressive agent in animal systems at levels far below those recognized as overtly toxic. Little data exist on lead's effects on the human immune system, especially in young children who are at greatest risk for exposure to this environmental hazard. The effects of environmental lead exposure on the human immune system were examined in a population of young children, age 9 months-6 years, from the urban population of Springfield-Greene County, Missouri. Reported here are data from 279 children with blood lead levels ranging from 1 to 45 microg/dl. White blood cell populations have been enumerated and examined for cell surface expression of activation markers. Serum has been analyzed for IgE, specific titers to Rubella vaccine, sCD25 (the soluble form of the IL2 receptor), sCD27 (the soluble form of the lymphocyte specific member of the tumor necrosis factor receptor family), and IL4 (the cytokine interleukin 4). Variation of these assays with age of the child was considered in statistical analysis of data. A statistically significant relationship of IgE and blood lead level was found in this population; as blood lead (PbB) level increases, IgE level increases. No other statistically significant differences between risk categories or other associations with blood lead level were found. The exact mechanism for this apparent stimulus of IgE-producing B cells remains to be elucidated. The development of allergic symptoms is often preceded by an increase in IgE. These data indicate that ingested lead could play a role in this process by stimulating IgE production.

Immunity in children with exposure to environmental lead: II. Effects on humoral immunity

Lead has been found to depress the immune system in animal studies at levels far below those responsible for overt toxicity. Literature studies in animal systems most clearly showed an effect of lead on response to a specific immunogenic stimulus. Data are sparse concerning the effects of lead on the immune system in the human population at greatest risk for exposure-children up to six years of age. This portion of the Phase I study reports concentrations of IgG, IgM, IgA, and IgE, as well as antibody titers to the specific antigenic stimuli provided by the vaccines against diphtheria, tetanus, and Rubella. The study population consisted of a group of 193 children, ages 9 months to 6 years, who participate in the WIC (Women, Infants and Children) and Lead Poisoning Prevention Programs in the urban area of Springfield-Greene County Missouri. Blood lead levels ranged from 1 to 50 μg dL(-1). Total Ig levels were determined and the data were analysed. No consistent significant differences were observed among the risk categories in the five age groups examined. A single Ig class in each of three age groups showed apparent significant differences among the various risk categories, but these differences were not correlated with blood lead. An analysis of specific antibody titers to diphtheria, tetanus, and Rubella was performed. Regression analyses of current data in Phase I of this study suggest a detrimental effect of lead on the antibody titres to diphtheria and Rubella.

Immunity in children with exposure to environmental lead: I. Effects on cell numbers and cell-mediated immunity

Studies conducted in animal systems have shown that lead is an immunosuppressive agent at levels far below those causing overt toxicity. Children less than six years of age are the population at highest risk for exposure to environmental lead; however little data were available to assess effects on the developing immune system in this age group. Reported here is the completed Phase I study on 193 children, ages 9 months to 6 years, with blood lead levels from 1 to 50 (μg dL(-1), recruited from the urban population of Springfield-Greene County, Missouri, through their participation in the WIC (Women, Infants, and Children) and Lead Poisoning Prevention Programs. This portion of the study dealt with enumeration of cells involved with the immune response andin vitro mitogenic stimulation of lymphocytes. The percent lymphocytes, monocytes, granulocytes, T cells (total), B cells, CD4+T's and CD8+T's and CD4+/CD8+ ratios were determined and the data were analysed. No consistent significant differences were seen among the various risk categories currently identified by the CDC. Though two age groups showed some possible effect of lead, none of the various cellular parameters within these age groups showed significant correlation with blood lead. The lymphocyte response toin vitro mitogenic stimulus was studied on 42 children (including 17 in risk classifications IIA and higher) using the mitogens phytohemagglutinin (PHA), Concanavalin A (Con A), and Pokeweed mitogen (PWM). No consistent statistically significant differences were seen among the various risk categories; the effects of lead, if present, are most likely subtle and obscured by the interindividual and time-dependent variation inherent in this type of study.

Structure and expression of major histocompatibility complex-binding protein 2, a 275-kDa zinc finger protein that binds to an enhancer of major histocompatibility complex class I genes

We have isolated a cDNA encoding a transcription factor that binds to the enhancer of major histocompatibility complex (MHC) class I genes. MHC-binding protein 2 (MBP-2) is a 275-kDa protein, containing two sets of widely separated zinc fingers and a stretch of highly acidic amino acids, a putative transactivation domain. The two zinc finger regions, when expressed individually as bacterial fusion proteins, bind with highest affinity to the MHC class I gene enhancer. Several proteins found in mammalian nuclear extracts bind the MHC class I enhancer in an electrophoresis mobility shift assay. Only one of these, a ubiquitously expressed factor, forming a slow-migrating retarded complex, can be supershifted by a MBP-2 antiserum. The same antiserum also precipitates a protein of greater than 250 kDa from COS cells transfected with a MBP-2 expression vector. Our data indicate that MBP-2 is a transcription factor involved in the regulation of MHC class I gene expression.

An epitope common to HLA class I and class II antigens, Ig light chains, and beta 2-microglobulin

The homology of class I major histocompatibility complex (MHC) antigens, class II MHC antigens, and immunoglobulin molecules has suggested their divergence from a common ancestral gene. We report here a monoclonal antibody (mAb), PAC.M1, which reacts with HLA class I heavy chains, HLA class II alpha and beta chains, and the light chain of human immunoglobulin by Western blot analysis. PAC.M1 reacted with 44 kd, 33 kd, and 29 kd species when tested on membrane glycoproteins from TRal, a B-lymphoblastoid cell line (B-LCL). Two-dimensional electrophoresis and Western blotting of TRal glycoproteins showed that these species had the appropriate electrophoretic mobilities for class I heavy chain and class II alpha and beta subunits. The presence of the epitope was verified on class II alpha and beta subunits by Western blotting of purified alpha beta-invariant chain complexes, and on class I heavy chains by Western blotting of purified class I antigens. The PAC.M1 mAb also reacted with immunoglobulin light chains when Western blotting was performed with normal human serum and purified IgG and IgM as antigens. While reactivity of the mAb with beta-2 microglobulin (beta 2m) was difficult to detect by Western blotting, binding of PAC.M1 to purified beta 2m was detectable in a solid-phase binding assay. Thus, PAC.M1 reacts with a determinant shared by a number of members of the immunoglobulin superfamily.

Cross-reactive idiotypes and common antigen binding specificities expressed by a series of murine B-cell lymphomas: etiological implications

A series of 27 B-cell lymphomas (designated the CH series), induced in B10.H-2aH-4b p/Wts mice by intense adoptive immunization with sheep erythrocytes, was found to represent a subset of the total B-cell repertoire. This subset was characterized by expression of a limited number of Ig heavy chain variable regions, as evidenced by the presence of cross-reactive idiotypes and common antigen binding specificities. Twenty-one of the 27 CH lymphomas studied were classified into five groups, defined by a particular cross-reactive idiotype; four of these groups were linked in a single network. Seven of 16 idiotypes defined by absorption analysis were present on lymphomas bearing either kappa or lambda light chains and so were localized to the heavy chain variable region. The surface Ig on 14 CH lymphomas was found to be specific for epitopes on certain erythrocytes (bromelain-treated autologous erythrocytes, sheep, and chicken erythrocytes) or E. coli. We propose that the CH lymphomas represent the malignant counterparts of a subset of idiotypically related, normal B cells in B10.H-2aH-4b p/Wts mice. Perturbation of this idiotype network, by hyperimmunization with an antigen for which some of the members are specific (sheep erythrocytes), increases the risk for neoplasia. Possible mechanisms for this are discussed.

Activity of antibodies recovered from immune complexes of ovarian cancer patients

Ascites fluids from ovarian cancer patients contain immune complexes (IC). Attempts were made to characterize those antigens to which the patient is reacting using antibody recovered from these complexes. Polyethylene glycol (PEG) precipitation and protein A Sepharose 4B affinity chromatography were used to isolate IC. Dissociation of the IC was achieved by G-150 gel filtration in 0.1 M acetic acid, 0.15 M NaCl. Activity of antibody preparations was measured using a binding assay with 125I-labeled staphylococcal protein A. Confluent monolayers of various cell lines (including human ovarian and cervical carcinoma lines, human lymphoblastoid cell lines, human and chick embryo fibroblasts) were used. Six of nine antibody preparations isolated from ovarian cancer patient IC contained at least some reactivity against all cell types. Specificity was further defined using cell adsorption assays and polyacrylamide gel electrophoresis. These results indicate what appears to be autoreactivity directed against a normal component(s) of many cells. No evidence for an ovarian cancer-restricted response was shown. Immunoprecipitation analyses showed several polypeptide bands on autoradiograms (49K, 46K, 33K, 25K), which deviated distinctly from the pattern obtained for whole cell extracts.

Antigen-induced lymphomagenesis: identification of a murine B cell lymphoma with known antigen specificity

CH12, a murine B cell lymphoma derived in B10 H-2aH-4bp/Wts mice after transfer of SRBC hyperimmunized spleen cells into an adult-thymectomized, sublethally irradiated, syngeneic recipient, is demonstrated to bear surface IgM specific for a determinant found on SRBC and ChRBC. The Ig specificity has been demonstrated by rosetting assays and complement-dependent hemolysis. The removal of CH12 surface IgM by capping with anti-mu or with anti-CH12 idiotype, but not with anti-gamma or with irrelevant anti-idiotype, eliminated the formation of rosettes between CH12 and SRBC or ChRBC. The absorption of CH12 Ig produced in vitro, with either SRBC or ChRBC but not with HRBC, removed all hemolysin activity against SRBC, demonstrating that only one CH12 product was responsible for the reactivity with both SRBC and ChRBC. CH12 has a surface phenotype of a relatively mature B cell expressing surface Ig (IgM-mu,kappa) and la antigens, but lacking Thy-1 or detectable Fc or C3 receptors. CH12 also expresses the antigen Lyt-1. Growth of CH12 in vivo or in vitro results in the generation of up to 3% direct PFC and serum hemolysin, which shows that CH12 is not irretrievably "frozen". The generation of PFC and serum hemolysin is associated with increased population density, and the rate of PFC and serum hemolysin accumulation cannot be explained by simple cell division. A continuously secreting hybridoma derived from CH12 was used to purify the CH12 IgM to facilitate studies of protein sequence and idiotype.

Antigen-induced lymphomagenesis: identification of a murine B cell lymphoma with known antigen specificity

CH12, a murine B cell lymphoma derived in B10 H-2aH-4bp/Wts mice after transfer of SRBC hyperimmunized spleen cells into an adult-thymectomized, sublethally irradiated, syngeneic recipient, is demonstrated to bear surface IgM specific for a determinant found on SRBC and ChRBC. The Ig specificity has been demonstrated by rosetting assays and complement-dependent hemolysis. The removal of CH12 surface IgM by capping with anti-mu or with anti-CH12 idiotype, but not with anti-gamma or with irrelevant anti-idiotype, eliminated the formation of rosettes between CH12 and SRBC or ChRBC. The absorption of CH12 Ig produced in vitro, with either SRBC or ChRBC but not with HRBC, removed all hemolysin activity against SRBC, demonstrating that only one CH12 product was responsible for the reactivity with both SRBC and ChRBC. CH12 has a surface phenotype of a relatively mature B cell expressing surface Ig (IgM-mu,kappa) and la antigens, but lacking Thy-1 or detectable Fc or C3 receptors. CH12 also expresses the antigen Lyt-1. Growth of CH12 in vivo or in vitro results in the generation of up to 3% direct PFC and serum hemolysin, which shows that CH12 is not irretrievably "frozen". The generation of PFC and serum hemolysin is associated with increased population density, and the rate of PFC and serum hemolysin accumulation cannot be explained by simple cell division. A continuously secreting hybridoma derived from CH12 was used to purify the CH12 IgM to facilitate studies of protein sequence and idiotype.