Arthroplasty
Prospective outcomes after primary and revision hip and knee arthroplasty.
Clinical Research · Orthopaedics & Traumatology
Orthopaedic Research Group
Professor N. Dimitrov, MD, PhD
Clinical research in orthopaedics and traumatology.
About
What we study.
Our focus lies in orthopaedic outcome studies and their effects in interdisciplinary settings.
Arthroscopy
Outcomes of arthroscopic procedures across joints, with structured pre- and post-operative measurement.
Registry science
Methodology and governance of prospective clinical registries in orthopaedics.
Interdisciplinary studies
Collaborative research at the intersection of orthopaedics and adjacent specialties: psychiatry, rehabilitation, and beyond.
Team
The people.
A focused group, with external collaborators where they bring expertise.
Principal Investigator
Professor N. Dimitrov, MD, PhD
Professor N. Dimitrov is Head of the Clinic of Bone Pathology and General Orthopaedics at USBALO “Prof. Boycho Boychev”, Sofia, where he has practised for nearly three decades. He is also a lecturer at the Department of Orthopaedics and Traumatology, Medical University of Sofia, and a member of the national Commission for Arthroscopy Training.
His clinical and research focus is shoulder surgery, arthroscopic technique, and upper-limb reconstruction, with published work spanning rotator-cuff repair, elbow arthroscopy, and ligament reconstruction. As Principal Investigator he leads the research programme of the group and serves as senior author on the majority of its published output.
Members
Nikolay Cherkezov, MD
Assistant Professor & PhD Student
Assistant professor at the Medical University of Sofia and a doctoral candidate at USBALO "Boycho Boychev". Oversees publication methodology: systematic reviews and meta-analyses.
Dimitar Tenev, MD
PhD Student
Medical doctor at USBALO "Boycho Boychev", Sofia. Responsible for patient data collection and the prosthesis registry.
Jakob Adolf, MD
Group Member
Clinical fellow in orthopaedics and traumatology at USBALO "Boycho Boychev". Enjoys statistics and study design.
Collaborators
Georgi Enev, MD
CollaboratorDoctor in the Department of Consultation-Liaison Psychiatry at Universitätsspital Zürich. Investigates translational aspects of psychiatric morbidity and musculoskeletal disease.
Publications
Recent work.
Our latest PubMed-indexed papers.
Bulgarian Translation, Cross-Cultural Adaptation, and Validation of the Simple Shoulder Test and the American Shoulder and Elbow Surgeons Shoulder Assessment Form
Does Previous Coronary Angiography Influence Complications in Total Joint Arthroplasty, and Should the Surgery Be Postponed?
Editorial: Epidemiology of orthopaedic sports trauma and injuries
From Bench to Bedside: Personalized Genomics in the Diagnosis and Treatment of Osteomyelitis
Is Septic Revision Knee Arthroplasty Associated With Higher Thromboembolic Events? A Matched Cohort Study
Projects
Active studies.
Active prospective studies.
Ongoing 2026-present
Endoprosthesis Register: Prospective Implant, Perioperative, and Outcomes Data for Hip and Knee Arthroplasty
Single-centre prospective registry capturing implant data, perioperative variables, and clinical outcomes for primary and revision hip and knee arthroplasty. The dataset anchors all other arthroplasty studies of the group.
Lead: Dimitar Tenev, MD
Ongoing 2026-present
PHQ-9 Depression Scores in Knee Arthroplasty Patients: A Prospective Observational Study
Prospective observational study of depressive symptom trajectories, measured with the PHQ-9, in patients undergoing primary knee arthroplasty. Pre- and post-operative time points capture the mental-health course alongside the standard surgical outcome set.
Lead: Georgi Enev, MD
Ongoing 2026-present
PHQ-9 Depression Scores in Hip Arthroplasty Patients: A Prospective Observational Study
Prospective observational study of depressive symptom trajectories, measured with the PHQ-9, in patients undergoing primary hip arthroplasty. Companion to the knee-arthroplasty PHQ-9 study; identical instrument, distinct cohort.
Lead: Georgi Enev, MD
Ongoing 2026-present
Functional Capacity (FUNCAP27 Scale) in Knee Arthroplasty Patients: A Prospective Case Series
Prospective case series measuring functional capacity with the 27-item FUNCAP scale across the perioperative course of primary knee arthroplasty. Pre- and post-operative scoring quantifies the patient-reported recovery curve.
Lead: Georgi Enev, MD
Ongoing 2026-present
Functional Capacity (FUNCAP27 Scale) in Hip Arthroplasty Patients: A Prospective Case Series
Prospective case series measuring functional capacity with the 27-item FUNCAP scale across the perioperative course of primary hip arthroplasty. Companion to the knee FUNCAP27 case series; identical instrument, distinct cohort.
Lead: Georgi Enev, MD
Activities
Where we'll be.
Recent team activities and upcoming congresses.
29-31 October 2026
XXVIII National Conference "Days of Bulgarian Orthopaedics and Traumatology"
Annual national meeting of the Bulgarian Orthopaedic and Traumatology Association (BOTA), in partnership with the Association of Physiotherapists in Bulgaria (AFB).
September 2026
Annual Team Meeting
Project review, planning and having fun 😄
Contact
Get in touch.
For collaborations, study enquiries, and academic correspondence.
Specialized University Hospital for Orthopaedics
“Prof. Boycho Boychev”, USBALO
Nikola Petkov Blvd 56
Gorna Banya, 1614 Sofia, Bulgaria
“Prof. Boycho Boychev”, USBALO
Nikola Petkov Blvd 56
Gorna Banya, 1614 Sofia, Bulgaria